Costco Beat Market Basket by Only 6% in a Boston-Area Price Survey, So Granite Staters May Not Need That $65 Card

A $100 cart at Market Basket would cost about $94 at Costco, a Boston-area price survey found.

That’s a smaller gap than many Granite Staters expect, especially considering Costco’s Gold Star membership card costs $65 a year.

Here’s how the math works for Granite Staters deciding whether that card pays off.

Note: This is general information, not financial advice. Prices and fees are subject to change.

How Checkbook Ran the Numbers

Consumers’ Checkbook priced a 150-item grocery basket around Boston and found Costco’s prices ran 6% under Market Basket’s.

The report was last updated in November 2025, and it doesn’t name the towns it priced.

If you shop at Market Basket in New Hampshire, your receipt may not match those Boston-area prices.

Warehouse clubs rarely carried the basket’s items in the usual sizes, so the same brands in other sizes were compared by unit price.

Price Gap in Dollars

Costco’s 6% lead means a $100 Market Basket cart would cost you about $94 at Costco.

If you spend $150 a week at Market Basket, that’s about $9 a week in savings before the fee.

Over 52 weeks that’s about $468, though only if Costco sold you every item in the cart at that 6% gap.

Break-Even Point

Costco’s Gold Star fee is $65 a year in the U.S., or about $1.25 a week.

The fee is the same whether you shop weekly or twice a year.

That’s after a $5 increase that took effect September 1, 2024 and moved the Gold Star fee up from $60.

Checkbook figures you’d need to spend more than $1,000 at Costco, on items Market Basket also sells, before the savings cover that fee.

Run it yourself: $65 is 6% of about $1,083 in Market Basket spending, which comes to roughly $1,018 at Costco’s prices.

If Costco sold you that whole $150 cart, the $9 weekly saving would cover the fee in a little over seven weeks.

Spread over a year, that’s close to $20 a week in Costco groceries.

If you only visit Costco now and then, the fee may not be worth it.

Package Size and Waste

Costco’s packages usually run larger than the sizes priced at other stores, which gives warehouse clubs an advantage in the comparison.

That tilts the 6% in Costco’s favor because this isn’t an apples-to-apples comparison.

Bigger isn’t always cheaper.

Packages save you money only if you finish them.

With an edge as thin as 6%, throwing out about 6% of what you buy erases it.

If you spend $94 at Costco on what costs $100 at Market Basket and throw out $6 worth, you’ve paid about Market Basket prices for the food you ate.

Small and Large Grocery Budgets

Costco’s 6% edge applies only to the items Costco sells.

Checkbook found Costco had 38% of the basket’s items, counting the same brands in any size, so say the same holds for your cart.

On $1,000 of groceries, $380 earns the edge for a saving of about $23, less than the fee.

You’d be about $42 behind.

A $3,000 budget fares better: $1,140 earns the edge and saves about $68, which leaves you about $3 ahead.

At $6,000, $2,280 earns the edge and saves about $137, or about $72 after the fee.

These figures assume the 6% holds on every item Costco sells, and an average gap can’t promise that.

Weekly Grocery Runs

The $1,000 break-even counts only items Market Basket sells too, so your whole-budget break-even is higher.

If Costco has just 38% of your cart, your total grocery budget would need to reach roughly $2,850 a year before the card pays off.

With the same 38% stand-in, a $50 weekly grocery run leaves you about $6 short of the fee after a year, while $100 a week puts you about $54 ahead.

BJ’s Wholesale Club had 73% of the basket’s items in any size, which shows how much the club you pick can change the math.

Market Basket's Low Prices

Costco's 6% lead came against a store whose prices ran 15% below the average of the Boston-area stores Checkbook shopped.

If your cart costs $100 at the average store, it would cost about $85 at Market Basket.

Another 6% off that $85 would bring the same cart to about $80 at Costco.

The gap was wider against Walmart, where Costco's prices ran 8% lower.

Market Basket's shoppers guide lists New Hampshire stores in towns including Seabrook, Nashua and Claremont.

Costco has a Nashua warehouse.

Prices cover groceries, not the miles to a warehouse, so a long drive to Nashua is a cost the 6% leaves out.

What Prices Leave Out

Checkbook's customer ratings gave Costco high marks for meat quality and overall quality.

Market Basket wasn't one of the area's top-scoring chains for produce or meat quality, though it earned higher marks on overall quality.

Costco's Nashua page also lists a pharmacy, an optical department and a tire service center, none of which a grocery basket measures.

If you'd use any of those, the card may pay off outside the grocery aisle.