Okay, here's the other side.
I don't know about the mob, maybe they control the escort services. Definitely stay away from those (but do look at the Vegas yellow pages for a grin to see dozens and dozens of pages listing escorts). $.5-$$ for the girl to show up and then if she doesn't just take your money and run you have to negotiate for any services ($$$ and up).
None of the following show any indication of mob control.
CG (Casino Girls) start at $$$$$ but many can be negotiated down to $$.
Craigslist is hit or miss like anywhere but prices start at $.5.
There are lots of AAMPs but most don't provide FS.
If you want a totally legal service, Pahrump and the closest houses are about 1.5 hours away.
There are also ads in the weeklies, like here.
Finally, several porn stars live or pass through town and are available if you want to live out a fantasy. Very expensive.
So, it will definitely cost you but there are good experiences to be had. Lots of people are dropping $$$+ to see Celine Dion and other big shows are all over $, so people are conditioned to spending money in Vegas. No wonder the sex trade is also cashing in.
To answer your original question, good info can be found in
http://www.usasexguide.info/