Amazon has the 12-Pack C4 Smart Energy Drink (Peach Mango Nectar, 12oz cans) on sale for $20 - 35% off coupon (first S&S order for this product) - 5% off with Subscribe & Save (cancel anytime) = $12 with free shipping on $25+ or with Prime.

Prefer a variety pack to try flavors? This 4-Flavor pack (12 cans) is $13 after coupon and S&S.