When it comes to international ordering to Canada I pay very close attention to who they use as a shipper. The tax free threshold here is only $40 vs $800 in the US, I really wish the USMCA trade agreement had fixed that. I often abandon orders at checkout if its a courier or some random shipper I've never heard of because you are guaranteed to be stuck with a huge brokerage fee. Regular postal or customs pre-paid are the only way to avoid surprises.
It does suck that the big courier companies now bill you after the delivery. No doubt their depot staff had to deal with irate customers on a daily basis when they arrived to pick up a held order and faced a ridiculous bill.
It also depends on what you order. Many bike hardware items are duty free (might still pay sales tax over limit), but clothing tends to have high duty rates. I think when I ordered a pair of shorts from wiggle I had to pay 18% on them.