If you are a media company, bidding on a PAC10 with UO & WA versus a PAC8 without them isn't just the difference of two schools. It is like bidding on a horse or a platypus.
If you are in the market for a horse, you don't simply adjust the price when it turns out to be a platypus. You walk away.
In this case, if you are a media company and UO and WA aren't in the deal, you move some PAC schools to B12 and you pay them there. You leave behind all the worthless schools you don't want. You don't simply offer the PAC less money.