The loser must pay their full dues before anyone else, within the first week of the offseason, or face escalation. A micro-punishment about promptness that brands them the league's most administratively supervised member. Commissioners love this one for obvious reasons.
Budget note: this one costs nothing but dignity, which makes it a strong pick for leagues that would rather spend the pot on the champion than on the loser's downfall.
Seen in the wild: fantasyleaguelottery.com