20 Costco Mistakes That Could Cost You

View Slideshow

Bulk-Buying Boo-Boos

Costco is practically a mecca for bargain-minded shoppers. Sure, you have to purchase an annual membership to get in the door — but in return, you get access to a world of high-quality goods at great prices, all backed by a generous return policy. 

Whether you need a new household appliance, a set of tires for your car, seasonal clothing, fresh produce, or the biggest containers of Lysol wipes you've ever seen, you can find almost any type of product at Costco.

But despite its legendary reputation for great prices, there are lots of common Costco mistakes that could end up costing you money. Make sure you're not doing any of the following. (Not a Costco member? You can apply here.)

Related: The Top Deals at Costco Right Now


Not Using Instacart

Let's get this one out of the way first. You almost always need a membership to shop at Costco — but there's one handy loophole. These favorite tips come from Jen Coleman and Laura Wiertzema of Costco Does It Again, who notes that "You can always Instacart Costco, even without a membership!"

Of course the prices won't be quite as good through Instacart as they are when you shop in person — but if you only crave a serious Costco bargain a few times a year and aren't buying big-ticket items, you can order from Costco via Instacart without having a membership. This is also a great way to get your Costco fix without ever leaving the house.

Related: How Non-Members Can Shop at Costco

Costco Check out
Costco Check out by Michael Lehet (CC BY-ND)

Shopping on a Sunday

Okay, let's say you want to visit your local Costco in person. We get it — the prices are best in the warehouse, and it's fun to explore the aisles and see which new items have arrived. But don't do your Costco run on a Sunday if you can help it. As Coleman and Wiertzema explain, the Sunday Costco crowds are just too crazy. Stick to shopping on weekdays instead, if you can.

If there's a big payday in your area — say, if lots of people tend to collect their paychecks on Fridays or on the first of the month — you can expect Costco to be as packed as it ever gets on a Sunday. Save yourself some trouble and stay home on those days, too. After all, that's part of the beauty of bulk shopping — you can usually afford to wait a while before the next trip.

Related: The Big Differences Between Costco and

Not Upgrading to the Executive Membership

Not Upgrading to the Executive Membership

If you're a frequent shopper, a basic Costco membership pays for itself pretty quickly through all the savings you'll reap. But as Matt, editor of Costco Insider, points out, if you spend $250 a month or more at Costco then you're leaving money on the table if you don't upgrade to an executive membership. That's because the executive membership comes with an automatic 2% cashback bonus on everything you buy at Costco.

An executive membership comes with other money-saving perks, too, including discounts on insurance and mortgages.

Related: Don't Miss These 20 Perks of Costco and Sam's Club Membership

Not Getting a Refund on That Executive Membership

Not Getting a Refund on That Executive Membership

If you purchase an executive membership but don't end up shopping enough to make it pay off, no problem: Matt at Costco Insider explains that Costco will actually refund the difference between that membership and a basic membership.

That's not an automatic perk, though — you'll have to remember to ask for the refund, and it only applies if your 2% refund is less than the cost of the membership upgrade.

For more great Costco stories and shopping tips, please sign up for our free newsletters

costco app

Not Downloading the Costco App

Skipping the Costco app won't necessarily cost you money, but it could cost you time if you forget to bring your Costco card on your next shopping trip. As Coleman and Wiertzema explain, you can use the app to get into the warehouse — and more importantly, check out with your purchases — even if you don't have your card.

No app? No problem. Go to the membership counter, show ID, and they can issue you a temporary paper membership pass for shopping that day.

Related: I Shopped at Costco for the First Time and This Is What I Learned

Costco Cart
Costco Cart by Susan Sermoneta (CC BY-NC-ND)

Buying Things You Don't Need

It's easy to get drawn in by Costco's prices, but sometimes, the giant quantities really are more than you can reasonably use. Yes, that set of dishes for 10 is a great deal — but do you really need that many bowls? If the answer is no, you could stand to save money by shopping somewhere else and buying the few items you do need a la carte.

Related: 10 People Who Shouldn't Shop at Costco

Costco Sample
Shal W./Yelp

Shopping on an Empty Stomach

Shopping on an empty stomach is bad enough, because suddenly you feel like you need all the food. But impulse buys are even more of a problem when you're in Costco, land of the free samples that are designed to provoke you into impulse buys.

And of course when everything around you is a bargain, it's even harder to resist.

Related: 12 Tips for Shopping at Costco If You Live in a Small Home

Costco by Anderson Depp (CC BY-NC)

Not Buying by the Case

How do you improve on Costco's already amazing prices? By purchasing bakery, meat and deli goods the same way Costco does — by the case. Look for special "by the case" price lists near relevant sections, or ask an employee if case pricing is available on your favorite items.

The obvious downside: You're going to need even more space than usual to store those new Costco purchases.

Related: 24 Costco Brand Products That Shoppers Love

senior woman online shopping
costco by anjuli_ayer (CC BY-NC)

Overbuying Out of Habit

It's distressingly easy to overbuy at any bulk retailer, as the packages are just plain bigger than what you'll find in regular grocery stores. Heading to the local grocer for two cartons of eggs is a very different experience from bringing home two Costco-sized cartons of eggs.

"We suggest you look more carefully at the expiration dates and really consider whether you'll get through the whole package before it expires," explains Matt.

Related: 28 Recipes to Use Up the Bulk Food You Overbought at Costco

Along With Over-the-Counter Medications
Along With Over-the-Counter Medications by Lisa Pinehill (CC BY)

Not Reading the Price Tags

It's hard not to admire the price tags in Costco — they're usually such a great deal, especially if you manage to catch something on sale. But take another look at those tags. As Matt explains: "Costco price tags can reveal a lot more than you might realize. Items that end in .97 mean they're on clearance. Items ending in .00 mean they're a manager's markdown. The star/asterisk in the top right corner means there are no more pallets of that item in the store, which is a sign that it's probably not going to be restocked that year."

Related: 25 Surprisingly Expensive Products From Costco

colorful sweaters

Not Snapping Up Seasonal Deals

Speaking of watching price tags, pay close attention to Costco's great deals on seasonal clothing and equipment. Sure, every once in a while, you might find something silly, like puffy jackets for sale during triple-digit heat in Arizona. But most of the time, Costco has great buys on season-specific clothing and recreational gear.

These items tend to sell out very early in the season, and may be replenished sporadically, if at all — leaving you to pay a much higher price to buy the same thing somewhere else.

Related: 20 Things You Probably Didn't Know About Costco

Not Shopping the Costco Website

Costco's in-store deals are great, but don't forget to browse their website, too. Sometimes you'll get lucky and score online-only deals that have the Costco prices you'd expect, but aren't available in the bricks-and-mortar stores.

Bonus: If an item is no longer available in your local Costco warehouse, there's a slim chance you might find it on the Costco website. Don't dally, though — those last few online items always sell fast.

Related: 20 Beauty Products Worth Buying at Costco

Foods with Freezer Burn

Not Checking Your Freezer Space

Costco's bulk buys may be large enough to feed a big family, but they're also great deals for singles and small families — as long as you have somewhere to put the extras! Yes, juggling piles of paper towels and toilet paper can be inconvenient, but it's fitting things in the freezer that really becomes a critical issue.

If you accidentally overbuy and can't fit all your frozen purchases into the freezer, you might find yourself surrounded by suddenly perishable foodstuffs that have nowhere to go.

Related: Costco's 28 Best Buys for Packing Your Freezer

AMC Theatres

Not Scoping Out the Gift Cards

Costco usually offers gift cards or gift certificates for local restaurants and attractions — movie theaters, water parks, and the like. You may also find gift cards for big companies like Apple, Cold Stone Creamery, and so on.

The downside: You don't get to choose the denomination of the gift cards, and they're usually for a pretty sizable price. But if those gift cards are for something you'd be buying anyway, they represent significant savings. For example, Costco might sell four $25 restaurant gift cards (a $100 total) for $75 or $80.

Related: Amazing Gift Card Deals From Costco and Sam's Club

Lie: These Are New Tires

Not Buying Your Tires at Costco

Buying new tires is one of the biggest regular expenses you'll face when it comes to your car or truck. Not only does Costco offer reasonable prices for swapping out your tires, they also offer free lifetime balancing, rotation, air pressure checks, replacement valve stems, and air pressure checks.

There's just one catch: Nowadays, they'll only install tires that you purchase at the warehouse. So if your local Costco has the tires you want and is close enough to serve as a service center, jump on the deal. 

Related: Tire Installation Cost Comparison: What's the Best Place to Get New Tires?

Costco Pharmacy
Charley C./Yelp

You Skip the Pharmacy

If you take prescription medications, check out their prices through Costco; you might be able to save some money. You can even sign up for additional discounts through the Costco Member Prescription Program

But the pharmacy/clinic corner of your local Costco is good for more than just prescription meds. Many Costco locations also offer free or low-cost screening tests for hearing, diabetes, osteoporosis and heart health. 

Related: 23 Health Products and Services That Cost Less at Costco

Not Shopping in the Photo Center

Not Shopping in the Photo Center

Pretty much any photo-driven items you can buy online, you can order and pick up for competitive pricing right in your Costco warehouse. Yes, that means canvas prints, holiday cards and wall calendars, all personalized with your photos — but we're also talking coffee mugs, photo books, and even fleece blankets with your photos on them.

Big Purchases Through Costco
Eric Broder Van Dyke/istockphoto

Not Making Big Purchases Through Costco

Costco is one of the last refuges of a no-questions-asked return policy (or at least not many questions). If you think there's something wrong with your product they'll take it back at any time, with only a few exceptions. If you're shopping for big-ticket items, passing up on that kind of guarantee could mean losing a lot of money.

That's why Coleman and Wiertzema love to buy appliances at Costco. "We know that if something goes wrong, they will take care of you," they say.

Related: Is Costco the Best Place to Buy a Car?

shopping for computer

Not Shopping Around for Certain Items

It's almost impossible to go wrong with most purchases in a Costco warehouse. As John, the blogger behind the site, affirms, "I have one rule. When in doubt, buy from Costco."

But he does allow that there are a couple of exceptions — specifically, computer items and designer eyeglass frames. In those cases, he says, there are so many vendors selling the same things online that it's worth taking a while to shop around. "Last 10+ years of being a Costco shopper, I didn't buy a single computer product from Costco," he admits. 

But John also adds: "If you're not a savvy shopper and you don't like the hustle? Then just buy from Costco. There are no Costco mistakes."