I'm 32 and recently married. I also have two large dogs. SF is completely out of the question for me. If I was younger and unmarried or had a working spouse I'd be more interested in trying it out purely for the experience of being out there (I'm told it's fun).
Having said that. Aside from the financial decision I have so little interest in being inside the giant tech bubble that most of my peers out there seem to live in. The vast majority of my friends in Austin are not in tech and I like it that way.
I totally understand your situation though. It's tough if you plan to stay at the same company and want to move up. Do you think you could negotiate a bigger bump for the move? It's one thing to be able to technically afford to survive out there. It's another entirely to be out there for 5+ years and then leave and realize you have basically nothing saved.
Oh, last point. I obviously have no idea what your relationships are like at your company but could you possibly make it clear to some people above you what your concerns are about the move and sort of get an idea for how likely it is you could move up and how long that would take? For instance if your manager thinks it's possible you could be in some new position in 2 years that pays a much better salary maybe it makes sense. Of course they cant guarantee that to you but you could judge the situation yourself.