WP:

Last time I reported someone for this, I went back two days later and the auction was gone. Yea, I'd say eBay takes action. I dunno what they do in the long term, but I've seen a few sellers disappear, and new ones appear selling the same thing, same area, but what have they lost? The FEEDBACK.

Bottom line is, if you do not report them, these guys will get away with scr*wing you over for what amounts to illegal postage. Its a self-policing system... i don't go ad-prowling to find twerps like that one, but when I do find one, I DO report them.