The phrase "pocket change" refers to a small amount of money that you keep in your pocket or wallet for small expenses or purchases. It is usually not a lot of money, just enough to cover small everyday things. Full definition
Foreign rights are sold so cheaply for most books, sometimes for as low as a few hundred dollars, that anything less than a 50/50 split barely produces pocket change for an author. (fonerbooks.com)
That is not pocket change, but if we are smart and responsible with keys, there is no need for this. (humblemechanic.com)
Sometimes, I got to go to the shop with him and I made a bit of pocket change running to the restaurant and getting coffee for everybody. (remonline.com)