If this version of the transfer portal and NIL continues, I expect to see a deflation in coaches' salaries rather than an increase. There have been coaches this past year (Brian Kelly and Mike Gundy) who have had part of their pay "allocated" to the school's collective. That is a formal way of saying we reduced your pay by $1 million in order to help pay players.
If it were a free market for everyone, with no dominant supplier or buyer, I'd agree.
Trouble is, that's not true for a relatively small number of schools whose athletic programs have de facto owners.
Oregon is one (Phil Knight). Tennessee is another (Jimmy Haslam). Michigan is starting to be another (Stephen M. Ross and lately Larry Page of Google). UTw and aTm are two others, though they have small groups of effective owners, not any single one.
Oklahoma State used to be in the club, but Boone Pickens' heirs don't seem to have the level of desire to influence the athletic teams as Pickens himself did before his death -- otherwise Okie Lite wouldn't have felt the need to allocate some of Gundy's salary to their collective.
I'm sure there are others, I just don't know who they are.
Those guys are literally buying wins, and their reward isn't financial. If it were, the economic principles you cite would apply. Their reward / return on investment is intangible.
It's the feeling they get from being an insider (in some cases,
the insider) at their favorite school. Staying at the President's Mansion for home games. Sitting in the President's Box and/or having multiple boxes at whatever they call their equivalent of our Founders Club. Riding on the school plane with the team to road games and having the hotel room next door to the President or Head Coach. Having no foolin' for real influence over recruiting decisions and coaching hires. Feeling like they're the driving force behind the wins.
I believe the only thing that will level the playing field is an anti-trust exemption from Congress and a CBA with a yet-to-be created players union.