Some of us older guys remember when these were all plentiful. My buddy bought a Polytech double folder (underfolding stock and bayonet) for $600 back in 1989 or 90.
And that reminds me that I bought a Sile import Norinco type 56 from a guy in New York that bought it to keep on his sail boat when at sea. He sold it to me for $550. I got it on a Friday and went to a gunshow with it on Saturday and a dealer offered me $850. That was the shortest time I had any gun, but should have kept it. It was unfired and mint with box.