Remember when Texas faculty all signed a thing outraged that Mack Brown was getting 5 mil a year? What simple times those were.
My answer is an honest "I don't know, but my opinion stinks because I think there should be a minor league where people who come to play sports go play sports, and colleges, where people come to play school". My opinion is not based in reality.
As a comparison for highly visible individuals, Mitch Daniels makes under 500k (admittedly with incentives, but still well under a million) and he's a successful university president.
and it should be based in reality. A big part of why it isn't is the anti-trust exemption that Congress grants the NFL to collude not to hire willing adults.