With orders of $25 or more, Amazon offers the Premier Protein 2.5-oz. Nutrition Bar 6-Pack in Chocolate Peanut Butter for $5.59. Check out via Subscribe & Save to drop it to $5.31. With free shipping, that's the lowest price we could find by $11, excluding the below mention. Each bar contains 30g of protein.

Note: This item is part of Amazon's "add-on" program and can only be purchased with orders of $25 or more. (Some customers may be able to avoid the $25 purchase requirement when checking out via Subscribe & Save.) Also, be sure to cancel Subscribe & Save after your order arrives to avoid being billed for subsequent shipments.

Don't need anything else at Amazon? For in-store pickup only, Walmart offers a 5-pack for $5.58.