This is purely a guess, but it could be that at least some of the guys who use BP or, god forbid CL, girls is the donation. While it is true you get what you pay for, maybe all a guy wants is a quick screw and either doesn't care who with, or can't afford one of the pricier ladies here. I have seen FS on BP for as low as $60 for 30 min. Wouldn't touch that with a ten-foot pole, but there obviously guys who would.