A piggy bank that is just a red plastic box with a black label. It could be illuminated with LED’s and feature sound FX (like inserting a coin into X game), but one less thing to worry about batteries and upkeep is a win-win if you ask me.
The “coin” gap on the left could be a handy place to store bills or credit cards.
Reminds me of an idea I had where you had have one of these Insert Coin devices connected between a game console and the TV, and the signal to the TV would only be active when a coin was inserted. Each coin was good for 30 minutes. Ideal for limiting kids’ gaming time, or teaching them to budget and save.