The secondary market is largely operated by retail galleries, and is where limited edition prints are bought and sold by collectors after the edition is sold out at the publisher. Generally prints offered for sale on the secondary market are at values above the original published price. Prices are governed by supply and demand on the open market, and are not set by the publisher. Prints in strong demand can change hands at many times the original published price. Only a very small number of aviation artists command a secondary market for their prints.