import duty sending used gear from Canada to USA

Duty calculator .com stated no duty applied to used gear purchased in Canada and shipped to USA. I purchased used gear from someone in Canada and having it shipped. The unit was manufactured in South Korea.

Has anyone had recent fees charged to a similar purchase? What is the safest, most efficient and least likely to be assessed duty or other fees?

Thank you.
I have bought several items here and from Canuckaudiomart.
One was a Simaudio integrated (made in Canada) another was Emotiva amp made in USA. One was shipped from Montreal the other Alberta. Both came via FEDEX no extra fees or duty. Just like buying from a USA seller as far as I could tell. Received both in three or four days.
Hope this helps.
You have to be really careful. I forget what the rules are because its been so long since I've bought or sold anything from Canada. But the reason I stopped in the first place was due to all this confusion with duty fees. Not only that, people try and trick you. If you are a buyer, the seller may claim there are no fees only to find out there are, and if you want the item, you have to pay. Once you pay someone, they don't really care because they already have the money.

Another bad experience I had was with Classe. I had a warranty issue and it had to go back to Canada for repair. Instead of sending the unit directly to Classe in Canada, they had me ship it to someone in upstate NY who put in their car and drove it in to Canada. That was OK. The problem was when they shipped it back to me. It was help up for over 3 months some place in Canada. When I finely got it back, the box was all torn up and had bright red stickers all over it.

I'm not saying something like this is definitely going to happen to you, but just be careful. For all I know, I could have been at fault somehow and just didn't know what I was doing.
The customs regulations are ridiculously complicated but at its simplest the issue is where the item was originally manufactured.

If the item was manufactured in a country that is a member of NAFTA (North Atlantic Free Trade Agreement, Canada, Mexico, etc.) the heavy customs duties don't apply. But if it were manufactured somewhere else, shipped to Canada and then brought into the U.S. the duties will be the same as if it were shipped directly from the country of origin to the U.S.

I learned this the hard way when buying a pair of ProAc speakers - English made - from a seller in British Columbia and having to spend an hour and considerable money at the border in order to drive them back into the U.S.
I purchased 2 items from Canada. In both cases, the seller drove them into the US and shipped them. Great sellers. I remember one said that there was a large FedEx store just across the border in the US, because so many people shipped to the US, especially for eBay. Other than that, I have been pretty careful not to get items from Canada, just in case.

Sfar's comments are important. US/Canadian made products should not be an issue, although they may be held up. Anything else may be a problem.

I purchased a pair of Ambience 1600 reference series speakers from the manufacturer in Australia. Shipping on them was $1400. I received a weird message from the shipping agency that the customs were going to dismantle the speakers for drugs unless I go to the Portland Airport and claim the item. So I picked them up. No duty. I have had them for 3 years and no bill yet. Australia is not NAFTA. Maybe I was just lucky.

Thank you for your insight. I will let you know how it turns out. They were 3 year old used Allnic Prepamp.

(Although I prefer to buy only US goods, Ross Parot was right in 1992 when he said if we approved NAFTA we will loose our manufacturing industry. I am not a big fan of Walmart who strong handled Rubermaid into producing goods below cost causing them to go bankrupt. On auction, the entire manufacturing line was purchased and shipped to China . If you question why Rubermaid is not the same quality it once now is manufactured in China.)
I bought an amp (made in UK) from a dealer in Ontario, shipped to Los Angeles. No fees if I recall correctly but the dealer indicated it was a possibility when he processed the sale. Not sure if it's relevant, but it was an open box demo.
I wanted to post my result.

3% import duty for non-nafta produced goods, new or used.

For me $300.

No other fees.

I did purchase speaker new from Australia and there is a trade agreement and no import duty. No import duty. From japan and I understand that soon Taiwan and South Korea will be included.

Buy used, claim less price. I did not do this.