1891 Liberty Head Quarter Eagle
Just 80 pieces were struck in Proof format, and PCGS estimates that a mere 40 coins are currently known to survive. The meager issue of business strikes for the year all exhibit a doubled die reverse feature, and apparently the Proof reverse die was not used for other 1891 quarter eagle coinage.
The example to the left was sold by Stack's Bowers Galleries in the May 2013 New Orleans ANA Auction, where it sold for $30,550.