I did think about booking her a few years ago when she came over on tour, mainly because of seeing her in films. Even then she was charging £500 an hour. I have paid that price before for other US pornstars but mainly younger and fitter ones, e.g. Gianna.
I would say if you are a real fan then go for it, you can always make £500 make in your day job, but since she's been around for a while so you don't know when she will retire. Personally I never went through with it as I see her as being past her prime. If she was charging say £300 I might have booked her.