Most tourers either have or will have a phone capable of navigation. That and a paper map should get you about anywhere you'd want to go. No dedicated gps needed.
For those of us too cheap or poor to pay for ??G phone service or for a bells and whistles gps, a bottom line
Garmin Nuvi will do the trick for <$100. Comes with the North American street map City Navigator, free updates. A true bargain.