First off I feel so bad for you, I hate being pin burned
While I fully understand the disappointment of the deal being cancelled and as a buyer I have a well known disdain for resellers and little sympathy for them in general, I myself would not be ok with technical problems during the last hours of my auction if I was the seller. If you were running an auction here on DPF and the site was down for hours, days etc. you would refuse to give up your pin to the highest bidder as well. I use a sniper program so I know for a 100% fact that my bids don't go in until the last seconds of an auction and I was probably set up to bid against you for the Cindy and my bids could not be placed, I was PISSED and was wondering what happened myself.
Regardless of circumstances, the seller should have made the starting bid the lowest he would take for it but most people never think that ebay might be down lol, it's not ever really an issue and people like the auction process as they think they might get lucky...as you did or thought you did
I personally HATE reserve auctions and refuse to bid on them at all. There is a seller that proclaims to be selling "1/2 a million pin in 180 days" (the number of days have been inflated several times lol) and all of their auctions have reserves as well as incessant shilling. They have some great pins but I have watched them sell and go back for sale over and over and over because of not meeting the sellers perceived value or because of the shilling/fake sale/relisting. I'm sorry but if you can't sell an item at what you think it's worth 3,4,5 times, it's time to accept that your hope or dream of a value is incorrect. We all dream of all auctions starting at .99 cents with no reserve and letting the actual market dictate the actual values of pins but we rarely see that happening. Because of that unless buyers STOP PAYING the sellers pin ransom the prices will always be dictated by greed and not actual collector values. That's why pins that sold for obscene amounts a year ago are falling and fast. Two years ago Rapunzel compacts were SELLING for $1500 if you could find them, now one sits on ebay with a buy it now of around $700 being listed repeatedly and the last one to sell sold for $450. Resellers greed causes huge bounces in values and it's a dangerous game to play when this kind of money is at stake.
As as for the legalities of the matter, ebay cannot FORCE a seller to deliver an item, yes they say binding blah blah blah BUT if a seller refuses to sell there official position is that "we cannot force them to sell it to you" they should punish them for reneging on the deal though because if they do it once hey will surely keep doing it. They do have the ability to suspend or ban sellers but I have never seen it happen for something like this.
I am soooooo happy that things ultimately worked out for you, we all want a happy ending, that's why we love Disney!