As was stated previously, they're worth whatever someone is willing to pay.
I bought one when they came out new, still have it, think the design is great, though hot and a bit heavy for how my hunting style has evolved since I first purchased it (more of a minimalist). I've owned a ton or vests over the years and have yet to find one built to that quality, and may never based on how most vests seems to be built today.
I will hang onto it simply because of the whole premise behind the vest, and the fact that I was fortunate enough many years ago to get to eat lunch with Bob Dixon himself. He was doing a seminar at a local sporting goods store, and I got to spend time with him and some of the folks from the store. My early turkey hunting years were spent watching the original Primos and Mossy Oak videos, which he was a big part of. We didn't have any turkeys to speak of on the places I had access to hunt at the time, nor did I really have anybody to teach me back then, as my father didn't turkey hunt at the time. So, I soaked up whatever knowledge I could gain from them (which was actually pretty good stuff since they didn't push many of the other gimmicks on the market today and just simply turkey hunted as I still do), hunted with whoever would invite me that had birds, and burned a ton of boot leather learning on my own. All that to say, getting to share a lunch with a guy like Bob was pretty darn cool to me at that time, and still would be today if he were around.
I've seen some of the high prices they command on eBay auctions, and don't view it any different from what some people pay for calls that they see as valuable.
