Russia
Nicholas I 1/4 Kopeck 1850-BM, KM-C147.3, MS64 Brown PCGS. From a series with a relatively very low mintage. While most 1/4 Kopecks were minted in the millions, those from 1850-1855 minted at Warsaw numbered only in the tens of thousands (though the Krause catalog does not list figures for this particular date, we can extrapolate that it was not very high based on the mintage figures from the other years).
Estimate: 300-400 USD