For me, it's $400-450 for fs. But that's only if they have a site with professional photos. That way that I know that they're dedicated to their work, and their rep is important.
Girls on CL who charge $350 are usually wannabes. They're hot enough, but by charging less than $400 they act like they're a high class SP giving a great deal. No website to establish a personality or rep...just a CL ad and jpegy photo. Therefore, their list of regulations and things you can't do, in their mind, are justified. "hey, you're getting a high-priced SP at a discount! Accept it!"