A method for guaranteeing a consumer a best price on an item purchased from a vendor in a consummated final first transaction, the method including, in certain aspects, including determining a refund due to insure that a consumer receives the benefit of a later better price, and displaying the refund...http://www.google.es/patents/US7769631?utm_source=gb-gplus-sharePatente US7769631 - Business systems with price guarantee and display
