Final note on adding a reserve... Nope... Cannot be done without controversy... Unless everyone agrees on one set standard to establish the value of a pin... Perhaps a mathmatical formula using the following info... Wants/Trades/edition size/original cost/age/condition/accessability/ever scrapped/universal desire... Hmmm that would work... No it would not!!! How can you establish value that everyone can agree on. I personnaly would pay more for an LE100 Goofy pin than an LE100 Stitch pin, but who else would...???
So on a reserve auction people could just always say the reserve was not met and waste everyones time as they fish for offers on their pins... That's called a trade thread I thought... So basically, if you are not going to take the risk stay off the playground... Just my opinion...
However on the flip side, as Unibear has pointed out, without a reserve system in place some higher end pins may never get listed for auction. I know I have a couple of pins that I bought for a fair deal on the secondary market (released well before I started collecting), and have tried to trade them for what I wanted with no luck. So I want to put them up for auction, but not let them go for a Hidden Mickey, a common rack pin, etc, if that is the only bid I get. My reserve would be very simple, I would look to get roughly what I have in the pin back, unless it was a pin on my higher wants, like in my case Scrooge related, I would go lower than what I have in it, similar to your "LE100 Goofy pin than an LE100 Stitch pin"
I think if we have a reserve system, the easiest way to do it is to list the reserve in the auction. In my case, if I have $40 into a pin, I can say something like this
"Unless the pin offered is a Scrooge pin from my wants, I am looking to get roughly what I paid for the pin back, whether in MSRP value or current value, which in this case is $40". If someone else has a different way to value the pin, they can do it that way as the reserve, like, must be an LE100, must have X trade ratio, etc. Ebay is the same way if you think about it, once you hit the reserve, you know it, and some people even list the reserve in the auction itself.
Edit: I looked through the auction forum, and there are a couple of auctions for LE pins that retailed well over $50 USD, have NO bids, and end this weekend. Based on the no reserve rule, if someone bids a hidden mickey for that pin, even though the auction states does not prefer Hidden Mickeys, the auctioneer is bound to do the trade. To me, that is how lopsided an auction could be without reserves.