Welcome to the Forum, riderfan.
The search feature on here is pretty handy. Type in "422" and you'll get about 3,000 results that you can pare down by relevance, date, etc. I think you'll find just about anything you want to know about these.
They aren't collectable, at least for the time being, but you can sure pick one up for a decent price. They've stayed in the $250 to $350 range for quite a while. Even an almost new in box model with cleaning kit and the original pack of ammo isn't much more than $400 or so, which seems low for what it is, but again, these aren't collectable yet and prices reflect that.
They and their brother 622s are fun to shoot and darn accurate too. If that style of pistol appeals to you and you want to invest in something a bit more valuable and more collectable, I'd suggest the 622VR (vent rib), especially in the rare 4 1/2" barrel length. In a full stainless steel model, the 2206TGT ("target) is the high roller and commands $600 to $700 or more depending on condition.