7 best and 7 worst things to buy at Costco

It's easy to walk into Costco, get totally starry-eyed over all the bargain basement deals, and completely disregard both your storage capacity and your budget.  

96 ounces of marinara sauce? Think of how easy dinner will be. 36 rolls of Kirkland paper towels? Cleaning has never been so fun. Five pounds of fresh strawberries? Jam, and smoothies, and pies, oh my. 

Those prices just suck you in, even if you do know deep down inside that maybe they aren't the very lowest, and maybe you can get a better quality product elsewhere. It's that Costco loyalty that gets us every time.  

Does Costco have incredible deals that beat out all their competitors? Absolutely. But we're here to dispel the myth that you should be buying every single item on your list at Costco. As amazing as the warehouse store is, it turns out that they're not the best place to buy all the things. Here's what you should and shouldn't buy from Costco.

Best: Kirkland bacon

Bacon is one of those things that most of us would happily spend more money on if it meant a superior product. That's because good bacon, with its perfect fat-to-meat ratio, and its perfect crispness, and its perfect thickness is worth a few extra bucks. But the good news is, with Kirkland Signature bacon, not only do you get the better tasting product, you also get the better deal.

According to Consumer Reports, Kirkland bacon was the hands-down winner in a taste test that included big brand names like Hormel and Oscar Mayer. In fact, they put it very bluntly, saying, "Kirkland Signature was the only excellent product," noting that "it crisped up nicely and consistently had balanced fat and meat flavors complemented by wood smoke and a hint of sweetness." And when it comes to cost, Kirkland bacon averages about $1.50 less per pound than other name brand competitors. 

And hey, don't worry about the fact that you're buying four packs at once. Bacon freezes beautifully, and knowing that you're never without your favorite cured meat on hand is priceless.

Best: Kirkland organic extra virgin olive oil

We've all heard the warnings about how much of the extra virgin olive oil out there is "fake," but that's not something you have to worry about when you buy Kirkland organic extra virgin olive oil.

According to a report from UC Davis, "69 percent of imported olive oil samples… labeled as extra virgin failed to meet the IOC [International Olive Council]/USDA standards for extra virgin olive oil." In fact, the Kirkland brand was the only imported olive oil sampled to pass muster. Those that failed did so due to one or more of the following flaws: "oxidation by exposure to elevated temperatures, light, and/or aging; adulteration with cheaper refined olive oil; poor quality oil made from damaged and overripe olives, processing flaws, and/or improper oil storage." In other words, those olive oils, no matter how expensive or how fancy the bottle looks, just aren't going to taste good.

So, if Kirkland organic extra virgin olive oil is such high quality, it must be cost prohibitive, right? Not so. According to Money, at under $19 for two liters (as of February 2018), the price is well below that of other brands (which may or may not be "real"). And don't worry about the size — if you're using olive oil on the regular, you shouldn't have to worry about two liters going rancid before you finish it.

Best: Prescriptions

Even with the best insurance, prescriptions can break the bank. But filling those prescriptions at Costco will at least make that hit to the wallet a little easier to swallow, even if you don't have insurance. 

In a 2018 study, Consumer Reports did a retail price comparison (the price a consumer would pay without insurance) of a one-month supply of five commonly prescribed generic drugs at more than 150 pharmacies across the country. The results were shocking: Costco beat out big name pharmacies by hundreds of dollars. The final price tag? The tab came to $105 at Costco, compared to Walgreens at $752, Rite Aid at $866, and CVS/Target at $928. Allow us to do the math for you: That's an $823 savings per month in the worst case scenario. Mind blown, right?

And here's the good news for non-members: Even if you did have to pay the $60 membership fee just to get your medications, it would be well worth it for savings like that. But you don't need that coveted Costco card to visit the pharmacy. A doctor's prescription is all you need to get your hands on those cheap drugs — though prices may be slightly higher for non-members.

Best: Kirkland organic maple syrup

When it comes to syrup, there are two camps: You either love the fake stuff, or you love the real stuff. If you love the fake stuff, keep right on buying that generic bottle for under two bucks. If you can't imagine pouring brown high fructose corn syrup on your lovely stack of pancakes, though, you should definitely be buying the real deal at Costco.

It's hard to beat both the quality and value of the Kirkland organic maple syrup. In a comparison of eight dark maple syrups, Consumer Reports found that though Kirkland brand ranked third (rated Very Good) in the taste test, it was 50 cents cheaper per serving than the syrup that took first (rated Excellent). The flavor is described as clean and complex for each of the top three, and it should be noted that the "Very Good" Kirkland was "not far off the Excellent mark with similar characteristics to those higher in the rankings."

The real kicker here is that Kirkland brand (at just 75 cents per servings) beat out the most expensive syrup (at a whopping $2.14 per serving) by five spots in the taste test. Proof that higher price doesn't always equal higher quality.

Best: Gas

Getting gas has to be one of the worst chores in the world. But since you have to do it anyway, you might as well couple it with a Costco shopping spree and a $1.50 hot dog and soda lunch. You deserve the very best for all that adulting. 

Other than the cheap eats and the retail therapy, filling up at Costco can save you a few bucks per tank, and hey, a few bucks a few times a month can mean a decent savings come year end. In fact, according to The Motley Fool, if you drive a lot, and therefore get gas more often than the average commuter, paying the membership fee just for the privilege of using Costco's tanks would be worth it, even if you didn't take advantage of all the other member benefits.  

The only downside here is that because Costco has such great gas prices, the lines can be long. Hit the pumps first thing in the morning to avoid the crowds (they typically open a few hours before the store does).

Best: Kirkland diapers

Let's face it: Diapers are expensive. If it was socially acceptable to wrap your child in newspaper, we might all do it to save a few dollars here and there, and plus, that's a heck of a way to reuse and recycle, no? (Disclaimer: We don't really condone wrapping your child in newspaper.) We do, however, want to know we're getting a good quality diaper for a good price, and that's where Kirkland Signature Supremes come in.

Reviews.com tested 33 brands of diapers to determine the very best one, and came up with a top pick for "best overall" and "parent favorite." While Kirkland did not win best overall, it did take home the prize for parent favorite due to their "value, stellar performance, and conscientious materials." 

Now, The Honest Company might have taken the title of best overall, but they sure aren't best overall on your pocketbook. At about 32 cents per diaper, The Honest Company costs almost twice as much as Kirkland Signature Supremes, which will run you about 17 cents each (prices effective as of April 2019). That's a considerable amount of money when you think about how many of those bad boys you go through in a day.

Best: Alcohol

There's nothing worse than bellying up to a bar knowing you're going to be raked over the coals for the one measly shot of well vodka in your cocktail. And nobody wants to overpay when they're buying booze retail, either. That's why you should make all your beer, wine, and liquor purchases at Costco.

SFGate compared the warehouse store's prices to those of BevMo, Safeway, and Trader Joe's, and the results were clear: Costco's value is hard to beat when it comes to brand name booze. As writer Filipa Ioannou reports, "for most items, Costco is the best and it is not close," and she says this is particularly true if you're buying large quantities of beer. At the end of the day, Ioannou concludes that the prices at Costco are so good that you could easily recoup a membership fee with the alcohol savings alone if you drink enough (not that we'd recommend that).

And don't forget, the brand name stuff isn't the only booze at Costco. You can score an even better deal on Kirkland Signature alcohol, which The Kitchn reports is typically 20 to 40 percent cheaper than the real deal. 

Worst: Electronics

It's hard to walk up and down the aisles with all those huge TVs, top-of-the-line laptops, fancy vacuum cleaners, and shiny new appliances and not be tempted to upgrade. But according to Howard Schaffer, founder of Offers.com, you can probably get a better price on deal and coupon sites. Schaffer explained to Kiplinger that since electronics tend to be bundled at warehouse stores, you might no be getting exactly the same deal, but it will likely get something very similar for up to 15 percent less. In particular, he advises, pay attention to seasonal promotions, like TV sales around the Super Bowl. As Forbes pointed out in 2018, Costco's Black Friday electronics deals aren't always the best in town, either. 

If you are a non-member who's considering biting the bullet for that new flat screen you've got your eye on, don't. The folks at Rather-Be-Shopping.com point out that plenty of stores will match Costco's prices, no membership fee required. That's $60 back in your pocket.

Worst: Coffee

There's no doubt about it: Costco's coffee is dirt cheap. Take, for instance, two pounds of Peet's Major Dickason's Blend. You will pay just $15.99 for the behemoth bag of whole beans at the warehouse store. Waltz into a stand-alone Peet's and you'll pay $15.95 for the same coffee. Well, 5 cents more isn't so bad… Except wait a minute, it's actually $15.95 per pound at Peet's (prices effective as of April 2019). Yep, you're paying twice as much when you don't buy those beans at Costco. So why wouldn't you?

Because coffee doesn't last forever. According to Death Wish Coffee, anything past two weeks and you're looking at a change and loss in flavor. And don't forget — the coffee you buy at Costco probably wasn't roasted that day, like it would be when you purchase it from a coffee shop, so you're already starting out behind, and in some cases it can already be weeks old. While it might be technically safe to drink several-year-old coffee, you really shouldn't if you care what it tastes like, even if it was really, really cheap.

Worst: Kirkland paper towels

We know that when it comes to great quality at great value, Kirkland is hard to beat. But it turns out that the products sold under Costco's private label aren't always top dog.

Clark conducted a strength test on four popular brands of paper towels (Viva, Bounty, Kirkland, and Great Value by Walmart) by pouring a cup of water onto each towel and then piling them with quarters while suspended in the air. Kirkland's paper towel came in third place, holding only 68 quarters compared to Viva's 88 and Bounty's whopping 120. Clark also reports that in Consumer Reports' ranking of the top five paper towels, Kirkland came in last, with Bounty again on top. They do note, however, that Costco's paper towels were the most affordable of the bunch — but if you have to use three in place of one, is there really that much of a savings?

Pro tip: You should buy your non-Kirkland brand paper towels at Costco. According to Business Insider's price comparison in August 2018, Bounty Select-a-Size were 28 percent cheaper at the warehouse store than from Amazon.

Worst: Kirkland AA batteries

With all the remotes and gadgets and toys in our houses that require AA batteries, you can't blame us for wanting to save a few bucks, can you? It turns out that Costco's Kirkland batteries might be less expensive than their brand name competitors, but they could cost you more in the long run. 

A quick look at the user reviews of this product on Consumer Reports indicates you should run, not walk, away from these batteries. With a dismal 1.7 out of 5 stars, the primary gripe is leakage and corrosion. 

Sentiments like this are common among the reviews: "Do not buy these batteries. They are less expensive; but, all will eventually leak and destroy your devices. I mean, all will leak in all devices: radios, flashlights, clocks, low power, and high power. Does not matter. I now purchase Duracell, and never had a problem. I kept buying Kirkland for years thinking a bad lot, NOT, all bad… Love Costco hate their batteries."

So, cheaper, yes, but could ruin expensive electronics? No, thanks.

Worst: Fresh produce

Though it might be tempting to grab five pounds of vine-ripened tomatoes or the giant tub of spinach because it's just so cheap, those produce purchases might be one of the worst buys at Costco. But it's not because of quality; it's because of quantity.

Business Insider spoke to Costco employees who explained that it's just too hard to consume that much fresh produce. "While our produce department is one of the best in the business, I personally don't eat veggies fast enough to buy in bulk, so two thirds of it will spoil before I eat it," one worker said. Another agreed saying that it was a "waste of money" since they couldn't "eat the huge quantity fast enough."

It makes sense — unless you're feeding an army day in and day out, it can be difficult to use up all that produce, especially since it doesn't all freeze well. Which, coincidentally, brings us to our next point: If you do want to stock up on bargain produce, head for the freezer aisle. According to Reader's Digest, there's plenty of frozen fruit and veggies there that you should be buying, and there's a much lower risk of it spoiling.

Worst: Canned goods

It can be hard to train your brain to remember that not every single product on Costco's shelves is the very best deal out there. You get caught up in the moment, and the next thing you know you've got a 24-pack of canned corn and a 5-pound can of baked beans in your cart. Before you get to the register, put those cans back. 

Kiplinger spoke to Teri Gault, CEO and founder of the grocery savings site TheGroceryGame.com, who explained that canned goods can consistently be found at supermarkets for a better deal. In fact, the savings can be up to 40 percent less than you'd pay at a warehouse store. And when the grocery store-brands go on sale? Forget it. Nobody can beat that deal. 

What about those tempting bulk cans? The deal there is just too good to pass up. Yes, it is a great deal, but as consumer savings expert Regina Novickis points out to Today, there's no way a typical family of two or four is going to be able to eat that 5-pound can of baked beans before it goes bad. At the end of the day, you'll throw out too much to make it worth your while.

Worst: Kirkland laundry detergent

In an odd twist of fate, it turns out that Kirkland Signature's environmentally-friendly laundry detergent actually scores a big, fat F from the Environmental Working Group, due to concerns of cancer, its effect on consumers with asthma/respiratory conditions and skin allergies/irritations, and last but not least, the environmentally-friendly detergent's effect on — you guessed it — the environment. Say what? 

In fact, most of Costco's Kirkland Signature line of cleaning products score an F from the group, with only one product — the dishwasher pacs — scoring a B. No, there was not an A to be found.

If things like this matter to you, you're better off skipping the warehouse's store brand. While Kirkland might be an irresistible deal, there are detergents on the market that are scoring far better. For instance, Whole Foods' 365 Everyday Value, The Honest Company, and Seventh Generation all managed to score top marks from EWG. Maybe knowing you have fancy laundry detergent will make chores more fun? Here's to hoping.