Very cool coin, and very collectible. This one is CU-1c-1973D-05: http://cuds-on-coins.com/lincoln-cent-cuds-1970-1979/ No idea on value. These cuds are formed when large pieces of the die are cracked off and fall away, basically a catastrophic die failure. As such they all tend to be pretty rare, because the die was normally taken out of commission shortly after it broke. The issue with price is really a function of how rare, are we talking about 2 known or 20 known. Off hand I would not be surprised if you could sell it for $40, maybe more.