If it's break-even, then other downsides come in. Constant uncertainty, harder path for long-term Big 12 teams to make the playoffs or establish themself.
If Clemson and Florida St increase per year per team payout by $7M, we break even financially. But probably not worth it to go through that for no real financial advantage.
They probably would have to increase per year per team payouts by closer to $10M for those 5 years to come close to being worth it