I bought my latest one off ebay, I got it with lifetime maps also. The previous owner gave me all of the garmin registration info for the unit so I could continue to get the map updates, otherwise the NuMaps update does not transfer to the next owner.
The unit was like new, came with all OEM mounts, box & documentation, I paid $149 for it shipped. If you don't care about updates they can be had starting at about 50 and up for a working unit.