Amazon cuts an extra 20% off a selection of Kellogg's cereal and Pop-Tarts when you click the "Clip this Coupon" button below the item's price on the product page. Plus, take an extra 5% off and bag free shipping when you add an item to your cart via Subscribe & Save. (Discounts will apply in cart.) Combined, that puts many items at lower prices than you'd pay at your local grocery stores. A couple of best bets, after all discounts: Note: Be sure to cancel Subscribe & Save once your order ships to avoid being billed for subsequent shipments.