My in-laws live in Cornwall, and I've shipped thousands of dollars of stuff to The Ship-It Shop in Massena. Less than $40 you don't pay anything, over that you pay tax. Never, ever had a problem.
What you're avoiding is incorrect duty fees which are rare, and huge private brokerage fees which are almost criminal.
Note that shipping from the US via USPS incurs NO brokerage fee; the brokerage is taken care of my Canada Post via your taxes. I ship EVERYTHING USPS now. It's sometimes cheaper than gas to pick something up, but often shipping to the states is free but Canada is terrible.