Most sellers only offer Free Shipping to buyers in their own country.
Paypal will not allow a buyer to add an address in another country to their account.
Either one of these may be the problem.
If you are buying outside of Canada and asking to have the item sent to yet another country, the seller may have a shipping fee in place for your country and another for the country you want to ship to.
You should also know that if he does not ship to an address that is in your PP account, he loses his Seller Protections from eBay and Paypal.
There is a work around, but it puts all the problems in your pocket not the seller's.
BEFORE bidding, explain to the seller where you want the item shipped and make it clear that this is not your address. Ask if he will accept payment by International Postal Money Order, which he can cash at his local Post Office. Get a firm quote on the shipping cost.
The seller is allowed to turn down your offer. If he does, do not bid, it will not go well.
If he agrees, you should be aware that there will be a delay in the IPMO getting to him. If he is honest (and most people are)
he can then complete the transaction. If he is not, there is tempation, since payment by money order leaves you with no comeback for non-performance.