There is no annual fee for the mercedes navigation system but there is a cost to purchase and install the system. The general cost of the system is from $800-$1200 depending on the cost of installation. http://www.benzworld.org/forums/audio-telematics-forum/1361910-install-navigation-system-w211.html
There aren't many handheld GPS navigation systems, but you can always find one for you. There is the Garmin GPSMAP 62S Handheld GPS Navigator, Magellan eXplorist GC Waterproof Geocaching GPS, and DeLorme Earthmate PN-60 Portable GPS Navigator. They cost around $130-400.
Your looking at about six to eight hundred dollars roughly for parts and labor.
Go to http://www.nextag.com/magellan-navigation-system/compare-html and this site will help you compare and find the best system at the best price for you. The price range itself looks like it will be in the 80 to 400 dollar range depending on what your looking for.
I think what your referring to is a GPS navigation system. These start at around eighty dollars and go up in price from there. They produce maps as you go by using satellite location.
$20.000
5000.00
about 500
it cost about 215.00 to refurbish them
I just paid $440 for pump and $187 for labor on a 2001 Navigator (100,000 mi)
at the Ford dealership, it cost $396.00 to replace.
2000