Origin of plug-nickel
A plug nickel or plugged nickel is a nickel (now a five-cent coin, but originally a one-cent coin and later a three-cent coin) where the "plug" (center disc) has been removed, thus decreasing the metal value of the coin.
What does worth a plugged nickel mean?
The phrases not worth a plugged nickel and not worth a plug nickel describe something that is worthless, something that is valueless, something that is useless and perhaps contemptible. ...
What's the meaning of don't take any wooden nickels?
The Chicago World's Fair in 1933 issued wooden nickels as souvenirs, and the tradition of wooden nickels as tokens and souvenirs continues to the present day. ... An American adage, "Don't take any wooden nickels", is considered a lighthearted reminder to be cautious in one's dealings.