LMAO ! I don't think there's a formula when you look at all the other ladies and the price variance. Has more to do with self worth when they look in the mirror. At least that's what I was told by a high end provider.
Thanks for the question Catman and I'm sure others will chime in on this one.
It takes a lot of trust both ways for it to work out.I have stayed the night with my favorite lady in Springfield twice and both times it was fantastic, but we are very comfortable with each other.