I have done some buying and selling into/out of Canada and have never been able to understand it.
The whole thing with the Post Offices is one thing, and the US Post Office blames it all on the Canadian Post, which may or may not be true (and I am one of the few people who loves the US Post Office and believes it to be a good and valuable service that should be preserved), but what about the "free trade" part of NAFTA?
Seems pathetic to ding little people trading items as small as individual keyboards, when there is supposed to be "free trade" between the countries.
"Free Trade" and NAFTA only applies to duty. If you import a non-NAFTA item you also have to pay duty, on top of brokerage and taxes.
Neat huh?
It is, of course, possible that customs neglects to charge you. Or that they set a bar higher than the law strictly requires. I think how non-corporate recipients are charged depends a lot on what channel processes your package. On packages originating from the US shipped non-USPS, I've never been given an inch and I've been charged outrageous brokerage. $70 brokerage for a $33 item once (this was UPS). On packages from the US shipped USPS, I have been given a break up to $25 or so but beyond that almost always get dinged. Sometimes I've had EMS packages come through with no extra charges for slightly higher amounts (up to $40 or $50), I think they might be prioritizing delivery speed over collecting every possible dollar - just a guess. On the other hand I've had EMS items come through with no COD fees, but an invoice shows up later in the mail.
On the other hand, I had a Filco from PCHome come through EMS with no fees whatsoever. I think this was declared in the $150 range. That's the first I've ever had something like that come through with no extra charges, but perhaps the customs group processing packages arriving from Asia-Pacific is more forgiving than those processing packages arriving from the US. Frankly, there's probably more money to be made by nickel and diming Canadians ordering from ebay, amazon, tirerack, etc...etc... than the occasional oddball package from Taiwan.