On shipments coming to Canada from the US, Fedex and UPS will bend you over big time for "brokerage fees" to clear customs for you over and above the freight bill. I would assume the same going the other way.
The best way around those "fees" at least in Canada is to have the item sent by Mail. Canada Post charges $5 to receive a US package and clear customs if they charge you at all. I've heard USPS is similar.
No duty or import taxes on goods going between Canada, US and Mexico. Thank You NAFTA.
Kevin