Each is based on only a need for USA maps. prices will change if you need more or differing maps.
Garmin, About $110 (wasn't able to find a decent page to post)
PharosGPS, Good basic program, $80 (
Pharos Science & Applications | Products| Smart Navigator & Maps| NAV80US)
iGo8, (they have updated to 2010 version and I cannot find a PPC version for sale)
CoPilot $30 if you download, $55 for DVD, $60 for SD card (it does have online features, but maps can be downloaded onto SD card if you choose to download it) (
CoPilot Live v8 | Features: ALK Technologies /
CoPilot Live v8: ALK Technologies)
I have iGo8, PharosGPS and CoPilot, all 3 are great programs, but CoPilot is great and comparatively inexpensive.