25 customs/tax fee to ship audio to Canada ??

Hi folks:
I sold my Sonic Frontiers Line 3 to a buyer in Canada about three weeks ago. I'm located in California and the buyer is in Ontario, Canada. I find that Canadian customs are holding the preamp, and want about $700CDN in customs/fees/tax before relinquishing the used preamp, which was declared and insured for $2,500USD. To me this excessive charge has been very surprising. Have others had the same experience? Are there ways to contest or overcome this problem? It would seem to make prohibitive any Canadian purchase of gear from the US. The whole problem is particularly disturbing given that one would think that there is such a thing as NAFTA. Also, the Line 3 is manufactured in Canada, and marked clearly as such on the paperwork. FedEx Ground was the shipper in this instance. Anyway, any advice would be welcome. Thanks!!!