USED ON A POSTCARD. The item “UNITED STATES #544 1 CENT POSTAGE STAMP USED ON POSTCARD RARE BOOK VALUE $2,500″ is in sale since Friday, August 07, 2015. This item is in the category “Stamps\United States\1901-Now\ Used”. The seller is “kginzburgster” and is located in USA. This item can be shipped worldwide.