What most have said: only for collecting or if you can inspect and preferably fire it first.
I dunno if QC or the soft materials, but lots of them are just unworkable, so I've seen the same one up for consignment from three people in a row at a gun shop for example. But, that was the early 90s. They must be getting rare now.
Also, every time I see one I giggle because the friend, counter guy — later a cop and now someone moderately well known in the industry — tried to get I and my friends to buy the lemon one he had in his shop, every time we visited. Once something about it came up and he was going to demonstrate how it wasn't plastic like a Glock or...whatever the setup was, but made of... [magnet he pulled out to demo it, falls off the side] "A metal-like substance."