I have a friend that's in the pros now. He did college football upto about 10 years ago. He was making about $2500 a game. Flew in on Friday and met with the crew ( all were professionals with other hi end jobs) did the game on saturday, and flew home on sunday. NCAA paid for everything from flight to food to hotel. Its very selective. They have recruits that come out and watch you just like they do with players to pull you up to the next level.
He loved it. Now he's doing pro games and still enjoys it. He retired from his other full time job, and now just refs Pro football. I catch him on TV everyonce in a while and make fun of him.
He makes alot more in the pros, but its never discussed. I was very impressed by his college crew. Judges, Mayors, Lawyers, Teachers.