Home prices in Austin are climbing though. It won't be too long until homes in that price range come with a minimum 45 minute commute.
Houses sell really quick too. If the current trend continues for another few years in Austin, it will be at Boulder, CO levels for housing (which isn't that far off from Bay Area housing prices).
Now compare Austin to Houston or San Antonio. (Besides, $100/SF is low unless you are talking about the East side.)
You can get quite a large house in Buda for $150K