As of July 2026 · 55 listings tracked across Amazon, Walmart & eBay
Right now the best value is 23¢ per oz — Body Fortress Super Advanced Whey Protein Powder High Protein Strawbe… (80 oz, $18.00) on eBay. See it on eBay →
Prices change fast and stock disappears faster — YMMV.
The pack-size trapThe biggest pack we tracked (160.8 oz) looks like the bulk play, but it runs 68¢ per oz — the 80 oz pick wins at 23¢ per oz. Bigger isn't automatically cheaper.
Median across all 55 tracked listings: $1.22 per oz. The worst deal we saw ran $2.27 per oz — same product category, 10.1× the price per unit.
The 12-month picture
This is our first month of tracked history for Protein Powder — the trend line starts here.
Lowest we've ever tracked: 23¢ per oz (July 2026).
How we figure this out
Once a month we pull live Protein Powder listings from Amazon, Walmart and eBay, read the honest quantity out of each one (ozs, in this case — the unit that actually matters), and divide the real price by it. Coupons that change what you'd pay today are applied; "subscribe & save" teasers are not. Then everything gets ranked by cost per oz, because a big box with a small number inside is still a small number.