Overwhelming Emotions
My first response is outrage, then comes frustration, then, disappointment in individuals among the human race, (of which I am not. Did I ever mention that I'm an alien? It's a choice. hahahaha)
I think you were thinking very clearly to keep all of this guy's emails because they are the best weapon you have. Funny how he's shooting himself in the foot and can't even see that he's the one holding the gun. I'm sure ebay will be just as outraged by the misuse of their site as we are. I also think that in leaving your negative feedback for this "morally challenged" individual, you should make it clear that the low rating you are giving is in relation to a legal issue and not just one of personal differences. That would scare me off from buying from anyone.
I must commend you on your quick action and for sending the letters, both sides, to ebay so they can see for themselves what has happened. I'm sure they won't let us down, but will step in and straighten things out. They will see that you acted in good faith by sending in the money in the allotted time and that the seller simply got greedy and changed his mind.
(This is just a little aside. I'm a bit of a people watcher. I like to figure out why humans do and say things in certain ways and at certain times. I think that when someone accuses us of certain personality flaws, generally, the accuser is the one who suffers from them. I could be way off here, but did you notice that he accused you of being greedy about $174, yet, by the same token, he refuses to sell you the wheels in a legally binding contract without that $174? <shrug> Things that make you go "Hmm".)
You WILL get your money back. Believe that, and then don't stop until you do. All your friends here are behind you. Go get 'em Tiger!!!
PS Your responses sounded very mature and well thought out, vs. his emotionally charged and orthographically-challenged ones.
Return evil for evil to no one...as far as it depends upon YOU, be peaceable with all men. Romans 12:17, 18