Quote Originally Posted by bobbinville
Isn't there a difference between numismatic value and the value of a piece of currency? I've got some US Notes; but there's no way that I would ever spend them because of their value as a collectible item.
Market vs. stamp value

The essence of legal tender laws? The attempt to stop Gresham's Law?
This presumes we are speaking of precious metal specie vs. clad coinage.