Amazon has 15-Pack 16-Oz Monster Energy Drink (2 flavors) on sale from $17.49 when you 'clip' the 25% coupon on the product page and check out via Subscribe & Save. Shipping is free with Prime or on $35+ orders.

Thanks to Deal Hunter phoinix for finding this deal.

Note: You must be logged into your account. Coupons are typically one use per account. You have the flexibility to manage your Subscribe & Save subscription at any time after your order ships. View Subscribe & Save filler items and our current Subscribe & Save Frontpage deals to unlock up to extra 15% savings when you have 5 or more items in your current monthly subscription.

Available (prices after 25% coupon and 5% S&S discount):

• 15-Pack 16-Fl Oz Monster Energy Zero Ultra, Sugar Free Energy Drink $19.24
• 15-Pack 16-Fl Oz Monster Energy Drink (Original) $17.49