Thumb Score: +40

Amazon [amazon.com] has 12-Pk 12-Oz Diet Coke Caffeine Free Soda 7 for $32.76 – $10 (multibuy discount) – 5% when you check out via Subscribe & Save = $21.12.
Shipping is free with Prime or on $35+ orders.

Instruction
Click here [amazon.com] and adjust qty to 7