If the seller is in the USA, he may be signed up for the Global Shipping Program. This gives him a tiny discount in his shipping costs, but puts a huge extra cost on the buyer, since it includes all appropriate duty and taxes.
Now, the duty and tax is probably correct enough, although Canada Post is sometimes sloppy about collecting and we love them for it. However, Pitney Bowes, who run the program for eBay WILL collect them along with a fee for brokerage before allowing the seller to ship.
It has become a good idea, if you are going to pay more than $20 for an item from the USA, to ask the seller BEFORE bidding, if he uses the program and if he does, explain politely why you will not be bidding on the item.
You can also ask if the seller is willing to ignore the GSP and ship by USPS/Canada Post, which will be faster (since the item does not have to be sent to a central trans-shipment point before being sent on to Canada) and cheaper (lower brokerage and possible that Canada Post will ignore the tax/duty).
