Amazon has 6-Pack 16.9oz. Diet Coke Soft Drink Bottles (Caffeine Free) on sale for $3.49 - $0.35 (5% Off) when you checkout via Subscribe & Save = $3.14. Shipping is free w/ Prime or on $35+ orders.

Thanks to Deal Hunter BBQchicken for finding this deal

Note, product must be sold/shipped by Amazon. 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.