Been there, done that JL!
I bought something from him, and he quoted me an outrageous amount for shipping. When I questioned him about it, he got all defensive and gave me some long spiel about having to drive 30 miles to UPS, pay for boxes, yadda yadda.
Then, when he wants to buy something from me, he turns returns the favor, like he did you. He wanted my brother to send him nearly a complete interior out of a car for next to nothing. I guess shipping to Maine is free, but shipping out of Maine costs hundreds of dollars.
I, and several others choose not to do business with him any longer. He is completely unreasonable to deal with. If he had any clue, he would realize that the drivers manifold with cat is nearly 3' in total length, and weighs 30-40 lbs!