Contact the seller and ask about his policy. Mention that he can ship up to four pounds by USPS First Class International service and have Delivery Confirmation on the package.
However, many sellers were unknowingly signed up for the Global Shipping Program when it was introduced last year. It is a comment on the unimportance of the Canadian market that US sellers are still at this late date discovering that they are advertising international shipping.
If the seller is adamant, well, you're not going to change his mind. And you might be shocked by the actual cost of shipping since the seller did not in fact have any input into his preferences.
In that case, ask for a Mutual Cancellation, which will in a friendly way, end the transaction for both of you with no black marks on either side.
