They deal is completely spot on and you have ABSOLUTELY no reason to be pissed at this guy. It sounds like you are a bit new at shipping/online parts trade.
“Shipping” does NOT mean what the guy payed UPS or Fedex.
Shipping means what he actually payed, plus his materials, plus whatever he wants to charge for his time. I even add the gas it costs me to drive to the shipper.
Its all a part of doing business and how its done. It sounds like the guy was more then accommodating. You AGREED to the terms (which were fair) You got lucky too because he was smart enough to use Greyhound for bumpers, UPS would have hit you for over $100.
Either way you have no case and no reason to start a problem. Hopefully you did not badmouth the guy on some other forum because then you owe him a apology as well.