In some circumstances, YES. Case-in-point, when Kevin Johnson fought harold Sconiers, we had to paid for Sconiers purse, training, etc. This is usually due to the original opponent backing out, not passing medicals, etc (any legit reason not to fight). The promoter usually pays less then what the other boxer will pay; Mark Holmes offered Sconiers $1,500 and we paid $2,500. Alot of stand in opponents get more money from the boxer, because the promoter, in some instances, already has a money order, certified check made out to original fighter. When Sconiers took the fight, he had literally a one week camp (Original opponent Stacey Frazier failed his physical), so we had to pay for his training camp. And with some Promoters, they take sanctioning fees out of the purses of boxers. Boxer A may have a $10,000 purse, but will only get paid $7,500 with the other $2,500 going to sanctioning fees...!!! It usually depends on the structure and wording of the promoter and boxer's contract.