Originally Posted by GarySaville
There are no trade duties between Canada and the USA. We have had FREE TRADEsince the 1980s. All Canadians or Americans are responsible for is the GST or State tax. If you send packages USPS or Canada Post, the most you will ever get hit is 5% in Canada or whatever the state tax is in the US. Most of the time I do not even get hit for tax.
HOWEVER, private shipping companies such as UPS and FedEX take advantage of customers by charging the receiving user fees for "processing" paper work at the border, which basically comes down to ticking a box that says "commercial goods". For their amazing hard work, UPS and FedEX will charge you 18% of your packages value.
Armaegis is correct with regards to duty but there's also a few other things that are not exactly true in your post. The tax charged depends on where you live in Canada, most provinces pay either HST or both GST and PST. I think Alberta and PEI are the only two that only pay GST and if all goes according to PEI's provincial government we'll be paying full HST when it comes into effect early next year.
It's really only the base service levels of UPS and FedEx that are bad, UPS Standard and FedEx International Ground, the services above those typically include brokerage fees so the receiver doesn't have to pay them. The main thing is to know which method the shipper intends to use.
Canada Post still charges brokerage fees, it's just usually a flat fee of $5 which I believe increases at a certain point of value of the package. I usually tend to prefer using USPS/Canada Post because they've been fairly reliable and the rates are usually reasonable, whereas UPS and FedEx can get out of hand pretty quickly if the shipper isn't getting deals on their rates. There's also a Canada Post outlet that's open till 8 pm about a 2 min. drive from my house so if I'm not home when the package arrives I can pick up later the same day. For FedEx and UPS I have to drive out by the airport and FedEx only has a window of an hour or two a day that you can pick packages up.