I lived in Austin for nine years and have been stuck in San Diego for three. I generally do not understand why housing is so much more expensive here, but I suspect many posters have already hit on the main points, availability of land (though less true for central Texas/Hill Country), less regulation, income disparity (though again not applicable to the Hill Country region).
I’m rather puzzled by people who do not think the outdoor recreation is there–that is one of the main reasons (besides housing expense) I want to move back to Texas. Hiking, camping, mountain biking, scenery, more trees, everything green–all better in the Hill Country. The only thing not available is surfing, though you can still make a weekend trip to South Padre, Corpus Christi, or Port Aransas if you miss the beach.
As for the greater Los Angeles/inland empire area, I will never understand why people live there. You might as well spend 1/3 the money for the same crap in Houston (with slightly worse weather).