As part of his work on "clandestine" Mint practices in the 19th century, Roger W. Burdette contributed to Newman Portal an 1859 memo from Mint Director James Ross Snowden outlining the offering of"master-coins," which Snowden defines as coming from "polished dies" with "extra labor and care." Collectors seem to like arguing over "proof" status for certain early U.S. issues, and, while thisdocument won't settle the debate, it is a step in the right direction. In any case, Director Snowden set the price for gold proof sets at $43.00 while silver sets were priced at $3.00.

Soon after, during the war, U.S.-issued greenbacks were no good at the Mint, and collectors wishing to purchase proof sets with currency paid a varying premium, depending on the latest fortune ofthe Union forces. Snowden further notes that the Mint will no longer trade pattern pieces in exchange for Washington medals needed for the Mint Cabinet, as most of the desired pieces had beenacquired. Snowden's book on Washington Medals, A Description of the Medals of Washington, was published shortly thereafter (1861).

Link to U.S. Mint Fixed Price Lists on Newman Portal:
https://nnp.wustl.edu/library/publisherdetail/512757

Link to Snowden's A Description of the Medals of Washington on Newman Portal:
https://nnp.wustl.edu/library/book/567813