It's somewhat cultural, but there are bars in Flushing (which are pretty much elusively Asian) that have been open under this model for years and girls who have worked at them for over a decade. In Tokyo, this has been going on forever, is fairly ubiquitous, and a Caucasian blond who spoke Japanese and was a 45 year old ex-model would have no problem finding as much work as she wanted.
If you are talking about actual prostitution, you'd be shocked at the number of $500 an hour women there are in NYC who are North of 45 (or even 50) (look at
http://www.amandamanhattan.com/amand...ou_gifts.html: take a guess at her age? hint: her TER reviews even go back to February 2000, or this one who's age I'll let others guess at
http://www.annekepleasures.com/donations.html - -yeah, she isn't $500 and hour, she's $400, but...................)