Amazon offers the Optimum Nutrition Opti-Bar Protein Bar 12-Pack in five flavors (pictured) for $26.99. Coupon code "OPTIBAR" cuts it to $18.89. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $6.34.) That's the lowest total price we could find by $9. Each bar has 20g of protein.