For a cheaper option look for the Garmin Quest. I have been using mine for 2 or 3 years now and it works fine, it wont take POI's though.
I used it for a trip I did to the Netherlands over the late May bank holiday and when a road it told me to use was closed, it found an alternitive route. Quite intresting it was to, one of teh roads (read tracks) was a dirt rad, with lots of potholes, trning into deepish sand.
Not to bad except that I was riding my 1500 goldwing with 3 other goldwings following, all 2 up !
Gave some of the locals who saw us going down the begining of teh track a good laugh though

Keith