There are less than 50 known examples of the 15c, with only around 10-12 in sound condition. This example is fresh and bright, in unused condition without gum as issued.
Although poorly centred (as is usual), the stamp is valued at $37,500.
Also featuring in the sale is a superb example of the 1901 Pan-American 2c invert, which is estimated at $45,000. The stamp is in exceptional condition, with full original gum (lightly hinged) and a deep, rich colour.
Chicagopex is the annual meeting of the Chicago Philatelic Society and will feature a philatelic exhibition, philatelic literature exhibition and the auction, as well as an awards banquet.
Paul Fraser Collectibles has a magnificent selection of rare stamps for sale.