Joining the Pac-12 is the best option, not just from a financial standpoint.
If the remaining members actually stay together and try to add 2-4 schools, it would likely mean adding UH and SMU. While it sounds cool to revive SWC rivalries, it would really hurt our recruiting efforts in DFW and Houston. That's my main concern. That said, I really doubt that all 8 members stay put.
I think the ACC takes West Virginia, and the Big 10 poaches Iowa State, Kansas, and OSU. Pac-12 ends up taking TCU and Tech. Baylor and K-State get left out. Baylor gets denied by Pac-12 for the same reasons as BYU, and I'm pretty sure K-State won't qualify academically for the Big 10.
Last resort to the AAC wouldn't be the end of the world, especially if they were to add BYU and Boise. I'm not sure if they could trim the fat and get rid of ECU and Temple, but that would be ideal in that scenario.