The Sterling X Caliber single shot was not made very long. One may have been tested by an IHMSA member in The Silhouette years ago, but I just be imagining that. I've never shot one, and in fact, have only ever seen one!
It was not an expensive handgun, and even though it is a bit of a rarity, I doubt that its value will ever increase dramatically. I see no reason to avoid shooting it to see how well it does, and if it performs to your satisfaction there should be no reason to avoid shooting it regularly. That's what these ol' handguns are for!
One bit of bad news is that if something should ever break, finding a replacement part will likely be a real challenge...but that's no worse than having a gun you won't shoot, anyway.
