Russia
Elizabeth Rouble 1758 CПБ-ЯI, St. Petersburg mint, Bitkin-286, Diakov-502, Petrov (3.5 Rub), AU55 NGC. Bright, and lustrous, with a few minor reverse flan flaws. A very rare issue (the "Ivanov" type) and the only example of this Bitkin number that has been certified by NGC, in any grade.
Estimate: 4500-5500 USD