Could make a fun mild femdom roleplay (with trust on both sides). Instead of paying her the money upfront, you put it on the side (so she knows it exists!), and the SP plays the part of the money-demanding escort wanting a bit more of the cash for everything she does. You end up paying the same for the same services, but in a different way. Would probably work best with a "bratty schoolgirl" type. Sorry, if that's drifting off topic, but it got me thinking.