I don't see how the Big 12 as a whole is overpaid. You could even argue they are underpaid.
If I've read the facts correctly, the Big 12 sold 57 games (19 to ABC, 38 to Fox) for $200M/year. That's essentially $3.5M/game, giving no credence to basketball or olympic sports. Numbers from here:
http://www.big12sports.com/ViewArticle.d...=205680799
The PAC12, for example, sold 45 games, although that includes the CCG which is more heavily weighted, obviously. That comes out to roughly $5.5M/game, giving no credence to basketball or olympic sports. Numbers from here:
http://media.al.com/sports_impact/other/...20here.pdf
Of course, it makes sense that the PAC would get paid more per game.
With more teams, the PAC has more inventory. The networks are getting to select the cream of the crop because they are getting a bigger selection of games/inventory (due to more teams) and are contractually obligated to air fewer of them. In other words, they aren't forced to air less desirable conference matchups. The PAC12 has retained the rights to those less desirable matchups and is trying to monetize them with a PAC 12 Network. So far, I'm not sure that's paid off. Maybe it will in the long run.
The Big 12, on the other hand, took a different angle. It basically sold all of it's inventory when you consider that it's letting each school retain rights to one game and that they sold 57 games to networks. Thus, the networks are getting all of the inventory- including the premium matchups (OU vs UT) and the undesirable ones which is going to make their average payout/game less.
The question is, which model is best? If the PAC 12 Network takes off like the B1G Network did, then obviously that model will win. But if it doesn't, the Big 12 model could work out better by letting each school monetize their 3rd tier rights. As we've seen, the larger schools like OU, UT, KU, etc, have been able to make a substantial sum off these 3rd tier deals.
At this point in time, the net-net is about the same with each school guaranteed roughly $20-21M/year (average over life of contract).
But, circling back around, is the Big 12 overpaid? I don't think so. They are getting less per game for a justifiable reason. If they were getting paid MORE per game than the PAC despite the networks having to take more crap inventory, then I would probably agree. But that does not seem to remotely be the case.