You have to make it clear that you are willing to walk if she she is not willing to negotiate. Those dancers are exactly like providers in that they want the most money they can for as little service as possible, and that means if she has a choice of fucking 3 guys for $400 each compared to 6 guys for $200 to make the same money, of course they will choose the former. Maybe ask your bud how much he is paying to fuck in the VIP, I bet it is not $400 each time.