I didn't pay anything extra for duty? I bought my wife a "Round" back in January, and while the Canadian dollar was crappy, I only payed 25% in CDN dollars over the websites listed price. So, not sure if I got lucky or you just didn't. :(
On a side note Canadian shoppers can find the watches at their local Best Buy... at least the current ones anyway. You might not get the style you want though, as they seem to be a bit limited that way. Pricing is usually close to the US price. I paid the extra to get the style I wanted for the wife.
They wanted to charge GST last time in Australia too, if you chose expedited shipping, even though the individual unit cost was well under our $1k limit. Reason was that the bulk of the lot was shipped to Australia, leaving it to Australia Post to organise delivery to individual backers.
It was a bit of a farce, they should just have shipped directly from HK or wherever; I sorted myself out by reverting to standard postage.
Reminds me of how here in Norway the postal service demand a flat fee for these things. Thus you risk paying more for the fee than the duty if the item is price just right.
I went in on the Pebble Steel in the past, and while I expected a Duty charge, I didn't expect it to be around 100$ Canadian.
EDIT: Sorry I meant Pebble Time Steel