According to The Smoking Gun Mike Tyson is most likely the lowest paid actor ever making a repeat an appearance in a sequel. Iron Mike got paid $200,000 for his role which is twice the $100,000 he got for the first film.
However, Bradley Cooper, Zack Galiafinakis and Ed Helms were paid each $5 million a piece for their roles in the sequel which is a huge jump for the $300,000 each were paid for the first Hangover film.
You know boxers are pretty notorious for getting screwed in the when it comes to money in the boxing game. Looks like that even extends to them when they move into the movies. Who in the hell made the deal for him for the film?