E-Bay Advice

Just wanted to get some input on this. I've been on e-bay for 3 years or so. Close to 50 transactions and never a significant problem. Last week I put a bid in on a used board, and won the auction for a pretty good deal. Prior to the auction I mailed the seller and asked how much to ship to my Postal Code (in Canada, he is in Utah). He stated that he checked for another guy in Canada and the shipping would be $17-$19. A couple days after I had sent payment of the bid price PLUS $20 for shipping, he comes back and tells me that shipping is now going to be about $76. When I pressed him about where he got the original quote, he said that "I am not the one who got the original shipping quote for 17-19 dollars, I gave another ebayer my zip code and he found it out and sent that quote to me"

Nevertheless, his e-mail to me about the shipping said "I checked for another guy in canada and it should be around $17-$19."

I did some searching and found some quotes for about $25-$35 dollars and told him I would give him and extra $10 or $15 if needed (I thought it was generous) but he is now telling me that the board has too much rocker and wont fit a 60x20x4 box, only a 60x20x5 box and this is oversized, raising the price.

I'm not really concerned about getting my $$ back as I think he will probalby give it if asked, and if not, I can certainly get covered through Paypal/Ebay. I dont know for a fact, but I wonder if maybe he didnt get the $$ he wanted in the auction and is trying to make up for it. I'm waiting to hear from him if he will pay the extra shipping above the $35, barring that, any other suggestions? Am I being unreasonable in suggesting that he pay a portion of the shipping?