Tortus, you are paying "New York" rates in what has become a midwestern business. Unless you are doing insertion or b/g g/g sets, the cost for models is relatively low these days. You may be shooting the wrong girls, ones that are already making $100 an hour standing around in a T-short.
I personally would recommend staying away from suicide girls. There have been some fairly bad stories about them. Further, signing any contract that limits you ability to shoot when and where you want, unless they are paying you major, major dollars is a no-no. They are, IMHO, trying to fuck you over.
Emma, we need to talk... I like McDonalds girls
Alex