There is no "set" guideline in boxing. Typically, you and your opponent sit down with your promoter (or manager) and come to an agreement on the purse split. Usually there's a number available to be guaranteed upfront (In Floyd vs Maidana case, it was 33.5 million to split between the 2 fighters. Floyd took 32 mill guaranteed and Maidana got 1.5 guaranteed)
I guess my question is can maidana get anywhere close to or more than 1.5 million dollars fighting anyone else. Because if so I tell mayweather to go fuk himself, on principal alone.
If fighters normally get 100k for a fight then maybe. But to me that still seems crazy.