I sold pixie sticks. Made a few hundred dollars. Had the princepal shutdown my operation, confiscate everything... including my lunch money.
How old were you, and was there a written policy explicitly prohibiting this?
Unless I were a tyke in one of the very early grades, it would have required a physical assault by a school official to get his hands on my money . . . and if not me, then my folks would have called the police to report a strong-arm robbery.
My inventory would have been recovered, too.