I'd bet it's a lot harder than simply looking good. The article stated that the incidents became longer and more complex the higher the price rose. The customer

I'd bet it's a lot harder than simply looking good. The article stated that the incidents became longer and more complex the higher the price rose. The customer expected to have a conversation. Given that she's now charging something only affordable by the upper/upper-middle class, one can expect her population to be highly educated. I doubt that if she were not already highly educated (and probably well-read, as well) she wouldn't be nearly as competitive. Of course, isn't that the market acting? How common is a highly educated prostitute who could choose between dozens of alternative, legal, well-paying professions. A lifetime of education is one hell of a marketable asset (and competitive advantage).