7 Mistakes First-Time Costco Shoppers Almost Always Make

You’ve joined the club — or you’re at least thinking about it. Securing a Costco membership is a huge deal, as it can save you a lot of money.

However, there’s definitely a right and wrong way to shop at Costco. It’s not uncommon for new members to make mistakes that can be costly.

This makes sense, as Costco isn’t like your average store. A combination of jaw-droppingly low prices and supersized bulk items can easily overwhelmed even the most — typically — disciplined shoppers.

Thankfully, you don’t have to worry about making these mistakes. GOBankingRates spoke with two shopping experts to round up seven shopping mishaps commonly made by first-time Costco shoppers.

Due to its overwhelming popularity, Costco is often quite crowded, so you need to be mindful of when you shop.

“If you go at the wrong time, you may have to wait in line and miss out on some samples, fresh food and discounted products,” said Sophia Phillips, lifestyle expert at CouponBirds. “It is suggested to go on Tuesday, Wednesday and Thursday later in the morning, as Costco always restocks overnight so that you can purchase the freshest products on the least-crowded day.”

“People always prioritize name brands over store brands,” Phillips said. “But Costco’s private label brand — Kirkland Signature — is really worth your attention for its high quality and low prices.”

In fact, you might find some of these store-brand items might actually be better than their name-brand counterparts.

“For example, Kirkland Signature Ultra Clean Liquid is ranked as the best value laundry detergent by Consumer Reports in a test of detergent, which beats out the name brands like Tide and Persil,” she said.

Additionally, she said many Kirkland products originate from well-known name brands.

“Kirkland Signature jelly beans, abundant in quantity, are made by the popular brand of Jelly Belly,” she said.

If you haven’t joined Costco yet, there’s two membership options to choose from. The Gold Star Membership has a $60 annual membership fee per household, while the Executive Membership is $120 each year per household.

For anyone trying to save money, the Gold Star Membership might seem like the obvious choice, but Phillips said that isn’t necessarily the case.

“With the membership fee of $60, the Executive Membership charges another $60 as an upgrade fee, which may be skipped by many customers,” she said. “However, executive members earn a 2% reward — up to $1,000 a year — on eligible purchases at Costco, Costco.com and Costco Travel, which may offset the fee.”

“Besides shopping, you can also gas up at Costco, which is cheaper than traditional gas stations,” Phillips said.

For example, as of Feb. 7, 2024, regular gas cost $4.19 per gallon at Costco in Culver City, California, according to GasBuddy. Notably higher, regular gas at both Shell and 76 costs $4.79 per gallon in the same town.

“Costco does outperform other retailers in the prices of many products, but not all products are the cheapest at Costco,” Phillips said. “Some grocery stores like Walmart may offer you a more favorable price for certain products.”

Therefore, it’s still important to comparison shop, even with a Costco membership. This can help you avoid spending more of your hard-earned money than necessary.

“Costco offers bulk options on almost everything you can find in the warehouse club,” said Samantha Landau, consumer expert at TopCashback USA. “However, this isn’t always ideal for smaller households.”

If you aren’t feeding a crowd, it’s important to think twice before putting items in your Costco cart.

“Make sure you’re buying bulk items only when you know you’ll use them or freeze them before their expiration date,” she said.

She said this will ensure you’re not wasting money by purchasing more than you need.

“It might be a better deal to buy in bulk from a cost comparison perspective, but if you don’t end up using the full product then you’re throwing money away,” she said. “You’re better off buying the actual amount you need to save money.”

Always make a specific shopping list before setting foot into a Costco store, Landau said.

“Since prices are so varied now from trip to trip, it could be useful to mark certain items as ‘needs’ and others as ‘wants’ to help you decide what fits best in your budget during your shopping trip,” she said. “At a store like Costco, it can be so easy to get distracted by great deals on items you may think you need, so it’s important to go in with a plan beforehand.”

She said your wallet will thank you later for making that list.