Forget that, 250$ as a company charge? She will easily want 750 a hour.
Unless you really have a thing for this porn star and don't mind spending 1000 a hour I'd say forget it.
As far as legit escort vibe, yea things seem legit here.
She told you 250 only gets her to the door so she seems upfront, though if she really is the porn star she claims to be? Doubt it. E mail her personal web site.