A couple ideas:
- It's a great IPSC gun, especially for beginners. Beautiful feel with the right grips, high grip to keep the muzzle jump to a minimum, very well built. After a couple years of competing, an owner may consider switching to a more expensive race gun
- There have been a couple new versions of the Shadow, since the original, so you may see a number of the black Shadows out there, as people may have upgraded.
It's absolutely not anything wrong with the Shadow that would cause these to appear on the market. I owned one a few years, and it never let me down.