What's with all the drama (and bigotry)?
If you can't meet a model's expectations (and/or visa versa), then it's a no go - this happens all the time. No big deal.
As far as deals go, anything goes - upfront payments, royalties, bonuses, top billing, limo service and any combinations thereof.
That's not to say that some combos just don't make financial sense for certain projects, but to start ragging on and whining about someone wanting more than you're willing (or practically able) to offer does not serve much purpose.
Asking if front-end payment plus rev-share is above industry norms is a legitimate and important survey, but to imply she (the model) was doing something wrong or malicious by dreaming high is neither fair nor professional.
If you can't afford what she asking and she is unable to accept compensation which better reflect your economics, move on...
-Dino