Originally, prices for the proof 50 State Quarters were quite high, with the 1999-S and 2001-S 90% silver proof sets selling for well over $150 apiece. As the series, which honored five states per year beginning with Delaware and ending with Hawaii, wound down, so, too, did prices. In 2009, the series was extended to include Washington, D.C., Puerto Rico, Guam, American Samoa, the U.S. Virgin Islands, and Northern Marianna Islands.
Most clad proof Statehood quarters can be bought for a song, though the 90% silver specimens are priced a little higher, reflecting their bullion content and their smaller mintages. While virtually all proof Statehood quarters were struck with extraordinary surfaces and details, proofs that are exceptional in quality and eye appeal sell for higher premiums.