BD-2 is one of four different Square Base 2, Large Letter varieties of 1820. All four varieties are very rare, if not, prohibitiveley rare, and BD-2 is rated as Rarity 5+ (20-25 known). However, as rare as this variety is, a few Mint State survivors exist in nice condition. Assuming the Bass Core Foundation coin is Uncircvulated, we know of seven Mint State examples. The finest of these a PCGS MS64, formerly in the Harvey Jacobson, Jr. Collection and the holder of the price record for this variety ($51,750). Why such a large percentage exists of the surviving population is a mystery.