How Far is too Far?

As I have begun to broaden both the role and location range of the job I am looking for, I continue to wonder how far is too far?

I left a good job to go back to school. I left it because it wasn't as close to my ideal job or preparing me for it as I wanted.

So now, as I start to broaden out from ideal again, what is too far? How far off should/can the role be, how far is too much of a commute to be worth driving from here and to require moving?

How come the popcorn I am eating tastes so good?