I very rarely hire if there's no reviews. If they're asking $250 or more, they better have a ton of amazing reviews OR look incredible and have at least a few decent reviews.
Add $50 to that figure if you're in a major metropolis with a high cost of living.
Also, I'll second everything said about lower rates for multi-hour appointments. I usually hire a guy for 2 hours for our first meeting anyway. It's long enough for us to chat and get comfortable before we fuck, but not so long that I regret it if it doesn't really click.
