The way I had it explained to me
when they tried to recruit me was that they are basically a referral service. The fee quoted should be all that is requested. The SP gets $200 per hour, and VE gets the balance for providing the referral, the advertising, and the driver.
The lady who runs it seemes really business oriented, professional and above board. I didn't get the impression that she would tolerate upselling. I would therefore assume that the quoted fee would be the total fee. If I was wanting to work for a referral service or agency, they would definately be on the top of my list. They do seem ethical.
With that said, I'm not sure how many ladies would actually be 'on' at any given time. Most of the ladies there are actually indepedants, and just book on when things are slow or they have unexpected free time. That alone should provide a non condusive atmosphere for upselling. I don't imagine that any successful indepedant lady would want to have their face and name associated with shady tactics.