We track the same 50+ staples at both Costco and Walmart, then normalize prices by unit cost (per oz, per count, per square foot) so the bulk math is honest. Below is the live verdict — plus when the $65 Costco membership actually pays for itself.
Updated daily. Cheaper price highlighted in green. See the full 50-item comparison below by category.
| Product (per unit) | Costco | Walmart | Costco saves |
|---|---|---|---|
| Kirkland / Tide Detergent (per oz) Laundry |
$0.108/oz | $0.130/oz | 17% |
| Bounty Paper Towels (per sq ft) Household |
$0.024/sqft | $0.031/sqft | 23% |
| Charmin Ultra Soft TP (per 100 sheets) Household |
$1.21 | $1.55 | 22% |
| Whole Milk 1gal Grocery |
$2.79 | $2.94 | 5% |
| Eggs Large Dozen Grocery |
$3.49 | $2.84 | −23% (Walmart wins) |
| Kirkland / Folgers Coffee (per oz) Grocery |
$0.21/oz | $0.28/oz | 25% |
| Bananas (per lb) Produce |
$0.69/lb | $0.54/lb | −22% (Walmart wins) |
| Kirkland Multivitamin (per pill) Health |
$0.04 | $0.07 | 43% |
| Gas (per gallon, regular) Fuel |
$3.18 | $3.39 | 6% |
| Kirkland / Members Mark Rotisserie Chicken Prepared |
$4.99 | $6.98 | 29% |
The honest answer to "which is cheaper" depends entirely on what you're shopping for. Here's the breakdown across 6 major categories.
By unit cost — the only fair way to compare bulk vs everyday packs — Costco wins about 68% of the time and saves an average of 14% per unit. The biggest savings are on paper goods (20-25%), Kirkland-branded vitamins and supplements (35-45%), coffee and pantry staples (15-25%), and gas at Costco fuel stations ($0.15-0.25/gal less than nearby Walmart).
The exceptions matter. Walmart wins outright when the math doesn't favor bulk: fresh produce and eggs in single-household quantities, small-pack snacks and items you'd waste in 24-pack form, and base electronics at MSRP outside of Costco's quarterly promotions. If you live alone or in a 2-person household and don't have freezer or pantry space, the bulk math collapses fast.
The other thing nobody tells you: the $65 Gold Star membership is a sunk cost that has to pay back. Most households spending $200+/month on groceries hit break-even by month 3 just on Kirkland coffee, paper towels, and gas. Below that threshold, it's a wash. Run the math before joining.
Costco and Walmart price the same products differently and update on different schedules. Costco runs quarterly catalog promotions and surprise .97 manager markdowns. Walmart runs weekly rollbacks. The "cheaper" retailer on any given product flips constantly, and bulk vs single-pack math means the right answer is per-household, not per-product.
PriceWatch tracks both retailers' current prices and normalizes them by unit cost so the bulk comparison is honest. We email when either retailer drops below your target — and flag when the unit cost flips so you know it's worth switching for that particular trip.
Stop guessing whether the bulk pack is actually cheaper.
Start tracking now