I don't know much about Austin, so I won't make a guess about there, but I know Dallas very well. For a provider to do outcall in Dallas, it could eat up alot of time in travel. It is a huge town and getting around is tough. Also, there has been a lot of heat recently in Dallas and maybe the providers just feel safer in their own place. Houston seems to be the same, trafic can be tough and outcalls may not be worth the time. IMHO.