Well he'll get negative trust but that's about it.  If you're really new here you probably aren't aware that scammers don't get banned.  We have a great trust system that's not broken at all.  Great algorithm, great coding; absolutely no understanding of human behavior.  But as whywefight has said, you didn't use escrow and you sent bitcoins first, and those two things have gotten countless members scammed on this forum.  Hopefully this monkeyfuck makes good on what he owes you but if not, better luck next time.