Amazon offers Prime members the Blue Buffalo Blue Life Protection Formula Dry Dog Food 15-lb. Bag in various flavors and breed sizes (Chicken and Brown Rice pictured) from $20.99 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, shipping costs $12.35.) That's $7 under our March mention and the lowest total price we could find in any flavor by $12.

Also available is the Blue Buffalo Blue Life Protection Formula Dry Puppy Food 30-lb. Bag in Chicken and Brown Rice for $36.99 with free shipping. That's the lowest total price we could find by $11.