This is an extremely important issue, and for two reasons. First, the business strike 1906 Liberty Double Eagle is a low-mintage coin with only 69,596 pieces produced. Second, the proof variant of this delivery is a genuinely rare coin in its own right. Out of an original mintage of 94 pieces, only 45-50 coins are believed to have survived in all grades. Most survivors are concentrated at or below the Proof-64 level of preservation, and Gem 1906 proof Double Eagles are very rare and offered less frequently than their counterparts from the 1898-1905 era.