It's a pretty capable module. But GEM was very advanced for its time, and they didn't add much new functionality after the SK-series of the late 1990s.

You should definitely plug it in and see if it boots up. One issue with these modules is that the "keep alive" battery dies, and it's soldered to the motherboard. I bought a new battery for mine but I need to take it to a tech to do the battery install.

GEM has been gone a long time and this is all orphan hardware-- parts & service are iffy so it represents a big risk to the buyer. You could start in the $400-$500 range and see if you get some bites.