actually the easiest and cheapest way is to ship to Point Roberts by Tswwassen.
i use The Letter Carrier
http://www.thelettercarrier.com
you send your stuff there and use your name and their address and when it gets all you need to do it go pick it up and pay $2US for the service.
i ship there all the time since some people wont ship to Canada. and since its still in the states you pay standard US-to-US shipping rates.
but you do need to cross the boarder so clean up your car with anything shady!!!!!! cause i've been searched enough times to know.....
and finally print out a reciept, ebay, paypal....etc....for proof of payment.
Al.