Tariff for used item from Canada to US


I bought a used Auralic streamer from Canadian Audiomart, got a UPS email holding the item and demanding $450 tariff. I emailed the seller, an audio shop in Canada if I could have it returned, and they said no. I paid through PayPal. The shop did mentioned it MIGHT got tariffed since its a Chinese made item. Is it fare that they refuse to take back? What would you do if you re in my shoes? The $450 tariff will make it as expensive as new in US.
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I just looked it up the company is based in HK. I believe the production is in China. 
UPS has been using a new system.  I don't know if this is a sub-contractor or new division.  Not only do they try to collect "legitimate" tarriffs, the fees involved are highway robbery.  I ship all of the time both ways across the border and only started experiencing this over the past year.  Calling UPS can be as impossible as calling the IRS.
If you keep calling, you might get the right person who will reduce the fees.  The other option is to tell the seller that you are stopping payment and they have to take the item back.  Offer to pay the return shipping to them and walk away.  This Canada-US thing is getting out of control.
I believe used items from Canada aren’t subject to tariff. But it’s based on the country of origin and this made in China component has an outrageously high tax due to our trade relationship.

I purchased a used dac from Canada, built in UK, and the VAT was about $40 (shipped UPS).