The 1926-D Buffalo nickel with its mintage of 5,638,000 pieces is a scarce semi-key coin in all grades and certainly so in uncirculated condition, in which fewer than 300 are estimated to have survived. There are handful in MS66 and a couple or so rare pieces in MS67, and examples in both grades inspire fervent bidding by registry set holders when a specimen makes its occasional walk across the auction block.