small change

small change (uncountable)

1. Coins of little value kept in one's pocket or bag.
2. (idiomatic) A minor or insignificant amount of money.

   The cost of toothpaste is small change compared to the cost of dental work.

3. (idiomatic, by extension) A person or thing of little importance or value.
   • 1988 Dec. 14, Vincent Canby, "Movie Review: Dirty Rotten Scoundrels," New York Times (retrieved 25 May 2016):

     He's a self-satisfied klutz who aspires to be a con artist. . . . Compared with Lawrence, Freddy is small change.

This idiom can also used in the negative to indicate a great deal of money:

The car he wants costs $38,000, and that's no small change.

• (coins of little value): loose change, spare change, shrapnel (slang)
• (minor or insignificant amount of money): chump change
• (person or thing of little importance or value): small potatoes