I don't understand the whole "I didn't buy it on Ebay" tack. If he found out about the goods on eBay, then it was clearly the eBay description that gave him the information that convinced him he wanted those goods. All the info he needed was in the eBay posting. It wasn't your responsibility to basically repeat all the exact same info you'd already put up on eBay just because he wanted to buy the stuff outside of eBay. The point is, all the necessary information was available, and he clearly used that information to make his decision. There wasn't any relevant information that you failed to make available. He's basically pissing into the wind at this point.
And yeah, after reading that other info it is clear that this dude's modus operandi is to act like he knows all, and when confronted, simply resort to trolling. He's on the internet for attention and that's it. Doesn't matter how many people he drags in or forums he bogs down. Sure, there are lots of selfish and self-centered people on the internet, but this guy is a scrotal abomination.