I'd cancel it solely over the "Shipping is too expensive!!" comment. Yes, shipping is expensive these days. You should have realized that when you agreed to the trade.

(I wouldn't judge them over what they're spending their free money on though, it's none of your business. You do have the right to be pissed that they're delaying it indefinitely though!)

Cancel it, sell the pawpads, wash your hands of the situation and order some parts from Newegg/Tiger Direct/Amazon/etc.