Only the guys who are elite, like mid to top fighters in the UFC and a few in Strikeforce make good money. They have long time sponsors who pay them every fight and get other perks.
A guy fighting in regional shows or is bottom of the barrell in top promotions has to have a second job. Many teach martial arts classes to cover gym fees. There are many expenses that people don't consider. Injuries are constant.
Not really. Even lower-tier fighter on the "big show" only make a few thousand per fight, meaning maybe $18K per year. Not bad, but not great. Of course, this doesn't count endorsement money, but again, unless you're high-profile that's not going to be too much.
Most MMA fighters have regular jobs they do between fights.
One of my managers at walmart is a pro fighters and a fairly decent one (not elite level but he has a pretty good record) and he is obviously working full time to support himself and his family.
MMA is not great money unless your in the ufc or similar big time promotion, even some of the big names there work other jobs (ie Shane Carwin)
The avg fighter may make 10k per fight, and fight maybe 3 times a year. but they also may make about 20k a fight based on endorsements ( basing this on what Pat Barry, who at the time was a middle of the pack HW with very little name recognition made) So your looking at maybe 60-80k per year. They may get a bonus for up to 60k for a good fight.