Sam’s Club is generally the cheaper option. Grocery prices at Sam’s Club run roughly 18% lower than Costco’s on comparable items by weight, and its membership fee is less expensive at both tiers. That said, the gap narrows or even reverses on specific products, so the real answer depends on what you buy most.
Membership Fees
Sam’s Club recently raised its basic membership from $50 to $60 per year, with its Plus tier going from $110 to $120. Costco’s Gold Star membership sits at $65, after its own increase in late 2024. That puts Sam’s Club $5 cheaper at the entry level and $10 cheaper at the premium level. Over the course of a year, $5 is negligible, but it does mean the baseline cost of shopping at Sam’s Club is slightly lower before you even load your cart.
Grocery Prices Overall
An AARP comparison of 30 grocery staples found Sam’s Club came in about 18% cheaper than Costco by weight. The study covered a broad mix: rotisserie chickens, wild salmon filets, baked beans, mayo, rice, pasta, eggs, pretzels, and orange juice, among others. That’s a meaningful difference if you’re filling a pantry with those kinds of basics every month.
A separate Business Insider comparison of 12 store-brand products told a similar story, though with a smaller gap. After adjusting for pack size, the Sam’s Club cart totaled about $150 versus $158 at Costco. That’s roughly 5% savings, which adds up over dozens of trips but won’t transform your budget on its own.
Store Brands: Kirkland vs. Member’s Mark
Both chains lean heavily on their private labels, and individual product matchups swing in both directions. Sam’s Club’s Member’s Mark wins on sugar by a wide margin: a 10-pound bag of white granulated sugar costs less than $7.28, while Costco’s comparable bag (organic cane sugar) runs $12. That’s nearly $5 in savings on a single pantry staple, though the Costco version is an organic product, which partly explains the premium.
Costco’s Kirkland Signature takes the lead on coffee. A bag of Colombian Supremo whole beans costs about $0.64 per pound less than Member’s Mark’s version, an 8% savings. On dish soap, the two are nearly identical: Kirkland comes in at $0.089 per ounce versus $0.090 for Member’s Mark, a difference of about 11 cents total.
The takeaway is that neither store brand dominates across the board. If you’re loyal to one club, you’ll win on some items and lose on others. Shopping lists heavy on pantry basics and household staples tend to favor Sam’s Club, while coffee drinkers and fans of Kirkland’s specialty products may find Costco competitive or cheaper.
Gas Prices
Both Costco and Sam’s Club sell fuel at a discount compared to nearby stations, typically 5 to 25 cents less per gallon. Prices between the two clubs tend to be close, so gas alone probably won’t tip the scale. One difference worth noting: Costco uses regular unleaded at its pumps, while Sam’s Club stations may vary. If you fill up 50 gallons a month and one club is even 5 cents cheaper per gallon near you, that’s $30 a year, roughly enough to cover the membership fee difference.
Where Costco Holds Its Own
Price isn’t the only variable. Costco tends to carry more premium and organic options, which can make direct comparisons tricky. The sugar example above is a good illustration: Costco’s product costs more, but it’s also a different product. If you’d buy organic cane sugar regardless, Costco’s price may actually be competitive with what you’d pay at a regular grocery store.
Costco also carries a wider range of Kirkland Signature products in categories like alcohol, clothing, and supplements, where the brand has built a strong reputation for quality at warehouse prices. Sam’s Club counters with tighter integration into the Walmart ecosystem, including curbside pickup and a Scan & Go app that lets you skip the checkout line entirely.
Which Club Saves You More
For most shoppers buying mainstream groceries and household goods in bulk, Sam’s Club will cost less. Lower membership fees and consistently lower shelf prices on staple items give it an edge that’s hard to argue with. A family spending $400 a month on warehouse groceries could realistically save $20 to $70 per month at Sam’s Club based on the price gaps found in independent comparisons.
Costco becomes the better deal if your shopping list skews toward its strongest categories: coffee, certain organic products, alcohol (in states where warehouse clubs can sell it), and Kirkland-branded goods you can’t get elsewhere. It also makes sense if the nearest Sam’s Club is significantly farther away, since the gas and time costs of a longer drive can erase a modest price advantage quickly. Your best move is to compare prices on the 10 or 15 items you buy most often, since that handful of products will determine which membership actually saves you money.