You may have noticed the following in each of the escorts advertising profiles:
"-------- charges for her time and companionship only. Anything else that occurs is a matter of coincidence and choice between consenting adults".
It's a legal formula. If extras were listed with their respective prices, then that would constitute advertising sexual services or prostitution. You can see what the escorts enjoy doing i.e. favourites, so you just have to enquire what exactly time and companionship includes when you ring them.
If anybody tries to get more money out of you then was agreed when making the booking or falsely advertises certain favourites, then either don't go head with the meeting or include it in a review.