There is no way to know what the actual amount is. The range is $300 million to $800 million., as is being put out in public. We'll just have to wait and see. FOX and the B1G have a huge interest in seeing ESPN take a hit by the ACC breaking apart, can't tell what they are scheming behind the scenes.
Yes, there is a way to calculate the minimum, as has been discussed ad nauseum.
1) The exit fees is 3X the annual payout. With a $42MM payout this year, if FSU announces by August 15, the exit fee is $126MM. Read the ACC bylaws.
2) The GOR has 13 seasons left, we know FSU must play this season, leaving 12 potential seasons to pay for. Again, the payout was $42MM. $42MM X 12 years = $480MM. Remember no conference will accept FSU unless they bring their TV rights with them. Otherwise the ACC and ESPN own the right rights to FSU games.
3) Add the exit fee and the GOR: $126MM + $480MM = $606MM. This is the minimum.
4) OU and UT set the baseline standard of a factor of 2.1, thus the exit fee $126MM + (rights buyback $480MM X 2.1 = $1.008BB) = $1.134BB, this is likely the target for the ACC and ESPN to begin negotiations.
The $300MM was floated by FSU, there were no ACC nor ESPN takers. Recall, ESPN is paying the ACC for FSU's TV rights, any agreement must include ESPN. We can conclude that FSU does not want to voluntarily pay more for FSU by moving them to the SEC, that is stupid business and damages the ACC, an ESPN property. Thus, ESPN would be losing FSU to Fox, don't expect ESPN to make it easy on FSU; nor will the ACC.