Bought one just like it, pretty much the same condition. Mine had been shot although very little. Put a 100 rounds through it, cleaned and put it away. Couldn't tell it had been shot 100 more times. Price was $800 here in Atlanta. Only one I had seen in person in several years. As with yours, no box/papers.
Roman, that is a very nice Colt Trooper MK III in .22 mag., an uncommon chambering. The Blue Book (34th edition - 2013 edition) claims the 100% value to be $550, with a 50% premium for .22 WMR, or $825 for your gun, for whatever the BB is worth.
If you bought the gun because you LIKE it, by all means, shoot the revolver!
If you bought the revolver to try to make a profit on it, keep it unfired.
IMHO, if you fire a couple of boxes through the revolver, do not holster it, do not drop it at the range, and carefully clean it after your range session, even an expert will not be able to tell whether or not the gun has been fired post-factory. I am NOT suggesting that you fire the gun, then fraudulently sell it as unfired!
If that gun were mine, I would keep it and fire it from time to time.