A buyer want to do a buy it now on a item I am offering
its 225 dollars plus shipping to Canada

how can I protect my self for paypal coverage and how would you ship item is 3 feet long and weighs 30 pounds.
What about customs?

Shipping for USPS is $66 assuming the package won't be considered over sized. Sure the guy even wants to pay that much?

I don't bother with international on big heavy items.

You can use usps international postage calculator.

Link

Same paypal protection rules apply - Only need delivery confirmation but to be safe use signature confirmation.

Accurate tracking only available with EMI(insurance is free for first $100 & additional amount can be purchased) & PMI(not very accurate).If buyer back out from paying taxes you have to pay Canada post to get item back.

FedEx will release package but bill seller if buyer don't pay brokerage (duties).

UPS has everything included- but shipping price is very high.

Try using a freight forwarder. They usually discount the shipping if you find one that uses USPS as their main carrier. I think Shipito might. Also it makes your buyer responsible for EVERYTHING. Customs, insurance, filling out the customs forms. Once your stuff is delivered to the forwarder, your part as been done and you are finished with the transaction. The rest is between the forwarder and the buyer. It's worth looking into for heavier or expensive items.