Exclusively for Prime members, Amazon offers the Monster Energy Drink 16-oz. Can 20-Pack in Lo-Carb for $24.98. Order via Subscribe & Save to cut the price to $23.73 and bag free shipping. That's $5 less than what you'd pay for any flavor in-store locally. (For further comparison, it's within a buck of an all-time low for a 20-pack.)

Be sure to cancel Subscribe & Save after your order ships to avoid being billed for subsequent shipments.