In order to encourage and promote the economical publication of worthwhile books on the history, archaeology, art, cartography, folklore and other cultural elements of Pennsylvania's heritage, the Pennsylvania Historical and Museum Commission, with the approval of the Governor, Auditor General and State Treasurer, is authorized to enter into agreements with publishers to subsidize the publishing of books in the said fields by agreeing to purchase a sufficient number of copies of a given book to make publication possible. The said commission may then resell such books at the State Museum or at the historic properties in the same manner as its own publications.