The best venue for selling ‘Limited Edition’ (ooh la la) stuff is an auction; hope a couple of buyers get that auction fever. Now you might have to pay out 20% commission to the house, so it's no guarantee of huge profits, but most of these guns were originally bought at fund-raising auctions, so that should tell you something.
If you post ten mass-produced Winchester 94 commemorative whatevers on the EE, it gluts the market. For some reason a gun auction with twenty of them will have the same bunch of guys bidding up every one.
I understand the sentiment, but I think that's a bit drastic. You may not be willing to over-pay, and sure, a gun that's ‘too nice’ can be a source of trepidation when it comes to taking it in the field and scratching it up. But I would gladly take an equivalent fancy edition over a standard grade *at the same price*, nearly any time I'm shopping for another gun. Whether I will pay a premium, depends on the particular gun, and how I feel at the time.
Ducks Unlimited also does good work, so even if your second-hand purchase isn't supporting them, at least you're promoting the brand.