"We may get a change that would allow us to have a playoff of fewer than 12, but I think this situation will certainly be a catalyst for discussion and we'll have to weigh whether this is substantial enough to add institutions," Bowlsby said. "Those are multifaceted decisions, and it isn't just about having a conference football playoff. But it's certainly a major consideration."

http://espn.go.com/college-football/bowls14/story/_/id/11995102/jilted-big-12-make-changes-college-football-playoff-relevance

Point being, there are 10 member schools in that league, all with differing perspectives on the matter. Some will just want to maximize $$$ and not expand. Others want the playoff and will expand only if they do not get that waiver. The waiver is the key decision, and BYU needs to pray they do not get it.

They are considering it though. Even Bowlsby himself said so. It is just a complicated question due to the different opinions from those 10 member schools. It is not just about $$$ either. Conference title game and $$$ are the 2 main issues combined, though.