I think to the right end user, this domain would have way higher value than what you can get from a reseller. A reseller might offer you high $xx for it, whereas you might get $x,xxx from an end user.
The big difference is that there are far far far far more resellers than end users and it can at times take you a while to find the right end user to buy your domain and as long as it sits undeveloped, it could potentially lose value.
I didn't do to much work into this domain but for the first few years of it's life it sat undeveloped as an alias to another domain that had to do with the military. In 2001 it got some development as a hobby website for aircraftand seems to have stayed that way until 2006. I highly doubt that the X-ring! AirSoft Hobby Site had amazing amounts of traffic coming to it but either way, it was still an alias website and that means that gamerx.com sat undeveloped for it's entire life cycle.
11 years however is a long time for own a domain and some people really like aged domains. The gaming industry is a multi billion dollar industry and you could easily brand Gamer X. Based on that alone, I give it the value of $x,xxx for the end user undeveloped and with proper development you could be sitting on a multi million dollar domain. Don't get me wrong, it will cost you greatly to properly develop the Gamer X brand but I think it might be something worth considering.