The amount of money a boxer earns per fight depends on their weight class, skill set, popularity and where the fight is. They are mostly paid by the round. For example, in 2014, a local boxer challenging a local opponent might make $800 for four rounds of fighting.
When a boxer gets paid, he is required to pay his manager and corner guy out of his own pocket, which is called a purse. Pay increases as boxers move up in rank, but so do the fees for their managers and corner guys. They are also responsible for paying their coaches.