Another way to look at potential teams is to look at their athletic department revenues. An obvious caveat, though: a lot of that comes from a team's conference and its TV contracts, which would change if the school changed conferences. So it's only really an apples to apples comparison if you compare two teams from the same conference - you're looking more for potential revenue than anything.
https://sports.usatoday.com/ncaa/finances
Couple things that stand out from that: the Pac-12 only has one team in the top 25. Trying to run a network on their own (without partnering with one of the big networks) hasn't paid off. That alone should be enough incentive for teams to jump. Also, despite their football success, Clemson is only the third highest in ACC revenue.