Generally, MSRP. It depends on the bookstore's agreement with the publisher. But, most are based on cover price. So, if a store sells the book for $5. The auth

Generally, MSRP. It depends on the bookstore's agreement with the publisher. But, most are based on cover price. So, if a store sells the book for $5. The author still gets $3.50 This generally doesn't apply if the publisher reduces the price for a 'sale period' though.