One of them was last year for $235, the one I had at the Muster last 2 years. Other was about 4 years ago from Gunbroker, but that one did have some "issues", but still is a shooter. I used it the first time at the 2010 Muster in Kansas.
Maybe the anniversary of WW1 has driven them up, I was used to seeing several on Gunbroker at any given time, but only a couple now. That one definitely looks worth bidding on in the 4-500 range, though. But as I said, it's now 100 years, so they're all going up.....