This is an on-going issue when trying to get materials across the border. My DH experiences it a lot as well, as he orders often from US sources.
As has already been said, items shipped FedEx will always have brokerage and handling fees added to them, making shipping exhorbitant. It gets worse for us, as we are rural with no local delivery and the nearest shipping center a 3-hour drive from here. Sometimes things were simply dropped off there for us to go fetch!
We have learned to not order using an on-line order form, but to call the company. Some places are fine, others need the personal touch. Sometimes we have trouble because we have a Canadian credit card! The hitches and glitches are unbelievable. It's truly worth it to shop in Canada only, as the prices are competetive, the shipping less and taxes predictable.
When you find a US company that will ship via post office, doesn't charge an arm and a leg to take that package to the post office, and will work with you, make a note and use them again!