Assuming Clemson or Florida St or other ACC teams, aren't coming available today or tomorrow the next target should be Hawaii.  Not as a full member, but as an independent with a scheduling agreement (like Notre Dame with the ACC....but with very very different logic) 

Let's start with a few baseline facts:

1. Right now, the Big 12 media deal is $32M/team/year (or $507 for the conference per year)
2. As of last week, the MWC TV deal was $3.5M/team/year (except for Boise St, who got somewhat more)
3. Hawaii currently spends approximately $5.6M/year in travel costs, across all sports
4. Hawaii (and Polynesian players in general, many of whom have extended family there) are often highly desired recruits
5. The Big 12 currently plays 120 games per year (16*3 OOC + 8*9 conference game)

So consider this.  The Big 12 approaches Hawaii and proposes a scheduling agreement wherein Hawaii will go independent, but 8 Big 12 teams will travel TO Hawaii each year to play Hawaii.  The Big 12 will own the media rights for all those games. In return Hawaii will receive $5M per year.

This has some clear and obvious advantages for Hawaii

1. Hawaii gets more money than they previously did
2. Hawaii has to travel less than they previously did
3. Hawaii gets to regularly play better opponents, which results in
   
   • more exposure
   • better recruiting
   • better (and more) gate receipts

So clearly a win for Hawaii (assuming they can find a home for non-football sports, which is admittedly not guaranteed.  EDIT: I've learned their other sports are already in a different conference, so this isn't a concern)

But does it makes sense for the Big 12?  I'd argue yes, for the following reasons

1. Cost of traveling to Hawaii isn't bad as a once-off every other year
2. Players aren't going to hate the idea of a trip to Hawaii, and this gives them a sort of boondoogle
3. Increased ability to recruit Hawaii and other Polynesians - for multiple reasons
   • Will be able to visit them during the season at least once every other year
   • Will be able to sell them on the chance to play in front of friends and family at least a few times
4. Most importantly though, this gives 8 Big 12 teams the ability each year to play 13 games, starting a week earlier
   
   • This means they can ALSO start practice a week earlier and get more practice every other year. 
   • Big 12 teams aren't losing any gate receipts because this is an additional game, beyond the 12 they normally would have. If anything, it actually makes it easier to justify the rest of the slate being a bit more home-heavy
   • And here's the kicker ... The Big 12 would control Week 0 and get a LOT more attention right off the bat
     
     • Games against Hawaii aren't going to draw ratings.... but most teams wouldn't be playing Hawaii in Week 0.  The Big 12 could schedule multiple showcase games against meaningful OOC (or even conference) opponents in Week 0, when there's almost no competition.  Those games are going to get the best networks / time slots etc and therefore ratings. 
       
       Yeah, later in the season Big 12 teams would have a game under the radar when they do go to play Hawaii, but it's a net win.  For exmaple, instead of something like BYU @ SMU on Friday night on ESPN2 against an NFL game, it would be highlighted as one of the kickoff games with a prime FOX slot in Week 0. 
       
       
     • Better TV slots and networks -> more attention -> improved recruiting and money
       
       
     • Previously the Big 12 was playing 120 games and getting $507M per year.  But now, they're playing 128 (a 6.7% increase).  Is the pay going to increase 6.7%?  No, because the added games aren't worth as much.  But the ability to own Week 0 and to therefore have more windows for bidders does mean it's probably increasing at least 2% or 3%.  2.5% of $507M is $12.7M.  After the payout to Hawaii, that means an extra $7.7M to the conference.  This more than pays for the cost of traveling to Hawaii 8 times, and that's before considering the recruiting and exposure wins that the Big 12 is getting.

It's weird and basically tells Hawaii that the most valuable thing about them is the NCAA rule allowing teams that travel to Hawaii to play an extra game and/or start the season a week early.... but that also IS the most valuable thing they bring to the table.  It requires some real out-of-the-box thinking....but guess which conference has the most out-of-the-box commissioner out there?