I'm also in Canada and I have noticed that shipping from the US here has been going up pretty significantly recently.
The shipping cost will depend on the box weight and size, and even looking at the same scale shipping cost can vary quite a lot depending on the statue.
As an example, I got the Wonder Woman Premium Format and if I recalll it right I paid around $80 CAD on shipping (to Ontario) + $20 as DHL's processing fee + 13% (of the total) as import fee.
More recently I bought the X-Men Rogue PF which has a huuuge box. Shipping alone was close to 100 CAD.
Regarding duty, I have been charged only once as the border agent or someone at DHL classified the shipping as a statue. I sent a request through DHL to have the border classify it with a different code (as a toy/figure instead of a statue - toys or figure don't require duty). The request was accepted and DHL reiumbersed me what I paid for duty.
All in all, I feel like it's getting more expensive and harder for us here in Canada to buy stuff from the US.
I'm thinking about buying a few more statues from Sideshow but I wonder if shipping them to a warehouse in the US close to the border would be a much less expensive experience. It's very very likely that import fees would still be charged but at least shipping could be a lot cheaper to the point where it's worth to drive across the border and pick up statues in the US.