• YMMV Stacking option: You can try clicking to the one-time purchase option, click the $3 coupon, click back to S&S, click 30% coupon, then checkout. Dropped to $10.74. 

Amazon has the 15-Pack 16oz Monster Energy Ultra Sugar Free Energy Drink (Variety Pack) for $25 - 30% off coupon (check "Save an extra" box, eligible on first S&S order for this product) - 5% off with Subscribe & Save (can cancel anytime) = $16 with free shipping on $35+ or with Prime. Roughly $1.08 per can.

• Other options for $17: Mango Loco / Peachy Keen / Ultra Black / Ultra Red / Original Green