China
People's Republic Four-Piece "Moscow Olympics" Proof Piefort Set 1980, 1) Archery 15 Yuan - PR68 Ultra Cameo NGC, KM-P112) Wrestling 20 Yuan - PR68 Ultra Cameo NGC, KM-P123) Equestrian 30 Yuan - PR68 Ultra Cameo NGC, KM-P134) Football 30 Yuan - PR69 Ultra Cameo NGC, KM-P14A marvelous set with a mere mintage of only 500 pieces for each type.
Estimate: 6000-8000 USD