A young adult (or middle reader?) book published sometime in the 1980’s about a boy who escapes from a New York City field trip and spends the day charmingly conning New Yorkers out of their money. The cover may show the boy dressed in a tuxedo, surrounded by a captivated street-corner audience.
This definitely sounds like “No Coins, Please” by Gordon Korman.
Holy cow, that’s exactly it! Thank you, Julie, so much! 🙂