Target offers the Up & Up Infant Formula with Iron 40-oz. Tub 6-Pack for $140.94. Click the "subscribe" box before adding it to your cart to cut the price to $112.75. With free shipping, that's $28 off, $18.79 per tub, and the lowest total price we could find.
Note: Be sure to cancel your subscription once your order ships to avoid being billed for subsequent shipments.