Ron Guth:
The Mint struck/sold 100 fewer Proof Half Dollars than in the preceding year, yielding a total mintage of only 575 pieces, and perhaps indicating collectors' disdain for the mostly brilliant finish on Proofs of this period. In keeping with previous years, Cameo Proof 1907 Half Dollars are quite rare and they represent rougly ten percent of the total population. PCGS has yet to certify a Deep Cameo example of this date and it is doubtful if such a version exists. The best value for this date is at the PR64 level (Brilliant finish only), where scores of affordable examples exist.