Yeah, eBay has tons of them. Use them for movie props all the time. If anyone is in LA there are plenty of surplus electronics shops that are overflowing with them. I used to search "cannon connectors" IIRC.

The steel ones ("Cannon connectors") are indeed very expensive: the only ones I have were removed from industrial equipment. However, for hobbyist use, I'd buy CPC -- Circular Plastic Connectors. Those are available in the same variety of pinouts and cost an order of magnitude less.