Isn’t about the sex, it isn’t about the pleasure, and isnt about the appearance/attractiveness gap, the money is about going away without attachment at the end of the night of fun . A girlfriend and a wife knowing about each other is a way to end up with neither and in court for 6 years. Expensive is just how any service fits it’s clientele.
You pay for them to go away and be quiet.
Its location location location. Bet many in her profession would like to have her ‘corner’