Don't be surprised if a handful turn up over the years. I was once a regular on rec.games.video.classic, and every so often some NOS would surface from the strangest places. One time somebody found a whole cache of old consoles, new in box, behind a wall in their shop. It turned out that back in the 80s it had been one of those computer boutique kind of stores and for some reason the owner built a section of wall over the back part of a storeroom, and left some stock in there.
What I can't understand about today's Amiga community is the reliance on the few remaining dealers. I can't recall the last time I went to a flea market and didn't find at least a couple of Amiga items, and the thrift stores are also a good source. You might not find what you want right away, but when you do find something it's generally extremely cheap.