France
Republic platinum Proof Piefort 50 Francs 1980 PR67 Ultra Cameo NGC, KM-P682. Mintage: 34. The first example of this massive double-thickness platinum striking that we have seen, with pleasingly cameoed, nearly flawless surfaces. Listed in the Standard Catalog of World Coins with a value of $8,700.
Estimate: 4000-6000 USD