Promotional value expires 90 days after purchase. Amount paid never expires. May buy multiple. Valid online only. Shipping not included. Same day shipping on most orders. The value of the deal represented is an industry average of the value of the entire value of books that will be included in each shipment. If not satisfied with the collection received, items are eligible for return and full refund from us. Merchant is solely responsible to purchasers for the care and quality of the advertised goods and services.