Have to agree. To expect or ask for a discount is, in my opinion, just bad manners. Should the lady in question offer it, fair enough.
I have seen a few girls over the past month, two of them twice. On all occasions, I was more than satisfied by them. I wouldn't be asking for a discount, because you have to think what the girls are doing - they deserve to be paid accordingly for their services. Yes, some charge well over the odds, but that hasn't been the case in my experience.