I would say SF costs are higher but, not very much, on everything than Texas until housing is considered. I don't think that is a very controversial assumption; even gas might be $4 in SF and only about a $1 cheaper in Texas.

Equivlalent lifestyle is always fuzzy: do I need a car if I live in SF? Maybe but many do well without. If you are into urban living...you wouldn't be very happy in San Antonio. In NYC, this is magnified obviously. You can also move out of SF, and unfortunately, many jobs are in the bay area and not the city anyways (so live in Mountain View vs. SF and work at Google).

For the record, I still think SF is too expensive and would prefer Seattle or Portland for quality of life reasons (but I'm a native PNW). I wouldn't dream of moving to Texas, I didn't even find Austin to be very nice; I don't like driving and haven't owned a car in over 7 years (when I lived in the Bay Area ironically).