Amazon offers Prime members four Milk-Bone Gravybones Dog Biscuits 60-oz. Boxes in Beef/Bacon/Chicken/Liver for $15.30 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $12.95.) That's the lowest total price we could find for this quantity by $34.
Of note, this item ships in 2 to 5 weeks.