Ron Guth: The 1851 Three Cent Silver is the second most common date in the series, nearly as common as the 1852. Normally, one would expect the first year of the type to be the most common, as they usually have the highest mintage and/or were put aside in large quantities by collectors. This may have been the case, but collectors seem to have favored the 1852 over the 1851 for some reason. In any event, collectors of today will have no difficulty acquiring an 1851 Three Cent piece, including Mint State examples.
The typical Mint State 1851 Three Cent piece grades MS-64, though MS-63 appear nearly as frequently. Even MS-65 and MS-66 examples appear frequently. According to the September 2011 PCGS Population Report, the finest examples of this date are 11 MS-67s.