Coaches & sports staff at the high level you are referring to, are NOT funded by the university budget. They're funded by specific athletic funds that is from sports revenue & that boosters pay into.
This is not an equivalent scenario - you're basically saying that a University should go set up an IT Booster Fund and have interested parties pay into it in order to pay these market rates - which they wouldn't (would you? I sure wouldn't).
"The other problem with the salary comparison is that Alabama taxpayers aren't paying Mr. Saban, and so his salary doesn't take any money away from professors. One of the benefits to come out of the rampant commercialism of college athletics is that media conglomerates and sneaker companies are willing to pay huge sums for the broadcast and apparel rights. Thus, Mr. Saban will be paid out of Alabama's $70 million athletic budget, with little or no impact on academic departments."[0]
[0] http://web.archive.org/web/20160325043141/http://www.wsj.com...