Proof 1906 Half Dollars mimic the other dates of the 1900-1907 era: they have small mintages; they are all scarce as Cameos; and they are exceedingly rare as Deep Cameos (where they exist). For some reason, the quality of this date is slightly less than its contemporaries. For most of the other dates, PR64 is the grade seen most frequently; for the 1906, it is PR63. Fortunately, there are sufficient quantities in the other grades so that collectors can be choosy.