Let's say ESPN wants to make these moves ahead of the 2025 season, basically ending the GOR 11 years early.
Right off the top, ESPN is paying the ACC $2.62B for those 11 years. Assuming they wanted 4 schools to go to the B12 and 4 to the SEC, they'd be paying just those 8 schools ~$2.73B for ESPN's share of those current conference deals for 11 years. They'd owe the B12 ~ $11m/school for 11 years. The SEC would be $51m/school/year. Wow, this is not off to a good start, but then again that's only ~$10m per year, which is really just a rounding error.
But wait, we still have to buy off those 6 schools that got left behind. What's that going to take?
First, ESPN owes them $17m a year for a 11 more years. That's $1.12B. Maybe those schools backfill and ESPN gives the the new and decidedly not improved ACC $10m/ (just for comparison, the AAC's getting ~$7m per year). That's a $7m gap, or $462m ($7m x 6 x 11).
Then there's the CFP money. P conference teams get about $4.8m/yr while G5s get ~$1.5m. Nobody knows what the next deal is going to be, but estimates are for 3-4x. The distribution model will likely change, but let's say an intact ACC would see everyrone's cut go up to $10m and G5s get $3m. There's another $462m our 6 after thoughts would be passing up as a non-power conference.
This is all money these schools will get if they refuse to go along with any negotiations. The only thing that's really negotiable is is the ACC exit fees, which are $120m/school. That would be a total of $960m which the conference is contractually owed and the schools agreed to. Maybe they'd go for 1/3rd or $320m/$53m each?
So, ESPN's paying more for less of what they already own, then they need to chip in another $1.25B or so just to make that happen? Doesn't seem like a good strategy. Yes, they could see some savings from operation efficiencies or increased values, but that's quite a hole to climb out of.