Beyond innumerable rules at home (no sneaking out of windows, no making potions out of toiletries, no growing mold in the bathroom, no snakes in the house, etc.) once as a kid I had $5 of birthday money burning a hole in my pocket, so at lunch I asked for as many $0.25 cinnamon rolls as I could get with a $5 bill. Although the cafeteria workers tried to talk me out of it, I spent the rest of the day parading around with a huge sack of cinnamon rolls which I didn't share with my classmates, as I was determined to bring my catch home to impress / share with my family. The same day, an announcement was made over the intercom to the entire school announcing a new two-per-person limit for cinnamon rolls. Details may be off as this was years ago, but that's what I remember!
I used to have people pay back borrowed lunch money in 5 cent cracker packages. I still remember the time i saved up about $5 in crackers because of one friend's debts.