I have the Garmin Quest. Is easy to use and can be used outside your car. You should be able to find one for under $400. I have used it throughout PA, NYC, NJ, VA, FL and GA without a problem.
http://www.garmin.com/products/quest/
edit - Where's the NSFW pics? I took a huge chance clicking on this. At least reward my risk-taking. [img]/images/graemlins/smile.gif[/img]