In the UFC the fighters generally know where they stand in the rankings and in popularity.
For example... A champion or high contender for a title are bound to make more than someone who just received a contract. There's only a handful of fighters who walked into the UFC who made ridiculous amounts right off the bat(Brock Lesnar) but in his case... he can sell pay per view tickets and subscriptions...
It comes down to... have they earned it and.. is the juice worth the squeeze. Some fighters getting paid 25k per fight win or lose with the potential to make the bonus for submission, KO, and F O T N. That is not bad IMO for someone who is new to the UFC.
But then there is Chuck Liddel and Randy... they are both greats and both former title holders who made over 6 figures per fight and still do yet they don't hold any titles no more... but thats where i said... have they earned it... and the answer is yes they have and champions... well we all know how much they make between a quarter mil to a half mil per fight.
Even the lower fighters are getting what 3 or 4 fights a year and clearing close to 100grand per year... hey thats pretty damn good in my eyes and it beats working a 9-5 job that you hate.
/rant and ramble