The year 1925 is notorious for poorly struck coins from heavily erorded dies. This applies across all denominations, but it is most apparent in the cents, nickels and dimes.
The 1925-D cent is nearly unrivaled as the rarest date with a full strike from fresh dies. Even the most advanced collector may have to compromise a bit with this issue. Dies were replaced individually as they failed, and it's not at all unusual to find such mis-matches.
Circulated pieces of this issue are common, and Mint State coins are fairly plentiful short of fully red gems. Strike will, of course, be the biggest deterrent to finding a suitable specimen.
Mintage:
| Philadelphia | Denver | San Francisco |
| 139,949,000 | 22,580,000 | 26,380,000 |