Ron Guth: The 1961 Doubled Die Reverse Half Dollar is one of the most dramatic, exciting, and valuable of all Franklin Half Dollars. However, be aware that there are other Doubled Die Reverses for this year, but they are not as dramatic and are far less valuable. The one to look for has very strong doubling of E PLURIBUS UNUM, UNITED STATES, and HALF DOLLAR.
As of May 2011, PCGS had certified 66 examples of this variety, usually in PR66 or lower. Only 10 earned the PR67 grade and none were graded finer. Apparently, cameo Proofs of this variety are extremely rare, as PCGS has graded only one (PR67CA). No Deep Cameo examples are known (yet!).