Turkey
Republic Valcambi Mint silver and gold 500 Lira 1979, KM931, the regular type in silver, PF69 Ultra Cameo NGC, and the same type in 90% gold, PF68 Ultra Cameo NGC. Both are noted by NGC as one of three struck. Commemorating UNICEF and the International Year of the Child with children dancing on the obverse.
Estimate: 1500-2000 USD