AT GNC, when you buy one GNC Pro Performance Pro Crunch Protein Bar 12-Pack in Peanut Butter Cup for $13.08, you can get a second 12-pack for free. (You'll need to add two items to your cart to get this price.) With around $4.18 for shipping, that's $0.72/bar, $13 off, and the lowest total price we could find for this quantity of GNC protein bars. Sales tax is added where applicable.
Of note, these items are on backorder and will ship in one to two weeks.