I'm still working on the approach thing myself.
As far as I know, typically in this industry the model is paid up front for a shoot, but I suppose you could always do a casting call style of shoot and let them know if anyone is interested. Just posting the girls you have available here in the content market can garner some real interest. Then let the buyers know your prices and do a half/half payment type - and pay the model out of that.
I really am in no place to be stating prices, I think it really depends a ton on your quality of shoot and models, which to me means your shoots will be a bit more expensive - as your photos are superb (and honestly should be out of my price range heh)
Good luck on ya, if you ever want to partner up in some way I'm here man, just email me through my website's contact form
