Russia
Nicholas II 50 Kopeks 1906 ЭБ, St. Petersburg mint, Bitkin-85 (R1), KM-Y58.2, MS61 NGC. Obv. Bust of Nicholas I left. Rev. Crowned double-headed Imperial eagle with date and value. Full, white, mint luster, with moderate marks and light obverse edge bumps. An extreme rarity in all grades. NGC has certified only 4 regular issue examples. total, and only two pieces in Mint State, with one example finer than this piece. The mintage is a paltry 10,009 pieces, but the number of pieces that show up in the marketplace would lead one to believe that the actual numbers extant is a minuscule fraction of that mintage.
Estimate: 5000-6000 USD