What is Braxton Miller currently getting for playing in front of 100,000 people? First, the "scholarship" is a negligible cost for the school. The "benefits" than the players get are simply the cost of doing business and keeping the cartel running. You can't count that as part of their compensation. It would be like claiming that the Mail Truck and uniform are part of the mail man's compensation. So, he isn't exactly getting a lot for all of that exposure right now.
Also, don't credit the university for giving the players exposure. The professional leagues would find a way to find the talent. The sports that don't filter through the college system have no problem identifying talent.
Finally, I don't understand the argument that paying the players will create some sort of competitive imbalance. The top ten grossing programs are perennial top 10 football programs already.