I'm not sure what other forum you post on, but some, like Ridemonkey, have a bad sellers and scams forum where such incidents are posted to warn others.

I think a lot of people (including myself at times) will post the item several places, especially if it's an expensive or niche item that may not sell on Ebay. I would definitely let any potential buyers know that the item is only available if if it doesn't sell at the auction.

When buying and selling on Ebay, you both enter into a legal contract of sorts. At the very least, you deserve to notify eBay to have your negative feedback removed and to push to receive the item that you legally won.