How the f*** does Bisping make that and why?.
Fights won in the UFC comes with pay raises.
Bisping has won something like 18 fights. If he started out with a salary of $12k his first win might've boosted him to $18k and the next to $24 or whatever. Eventually, after 18 or so wins (and only 2-4 losses) he's raking in $425,000.
Its also good for UFC & MMA expansion. If young people in the UK look at Bisping and see how much he makes, it gives them a goal to shoot for in the same way some take up golf thinking they can make a career out of it like tiger woods.