I really am fascinated with the large belt fed WWI machine guns. I want a machine gun and have been saving/selling to buy one. My question is why are they so much less expensive than M16s and HKs? Portable/handheld I get. Is it a parts availability issue? I've just started looking so I don't know the market at all. Just seems like the old trench warhorses are about half a sub gun or rifle. Any input?