There are actually several types of "tax" that can be levied when you import consumer products, and tobacco has its own special category.
The most common are duty/excise tax, regular sales tax (GST or HST depending on your province) and of course the tobacco tax. (I am simplifying things a bit, the regime is very complex).
I've never had to pay duty or sales tax on a pipe that I've imported, but I've always ordered pipes separately from tobacco.
Tobacco products I've found are luck of the draw. I'd say they get caught about 35% of the time. However, about half of the time I've been caught, the CBSA has only applied the regular GST/HST amount, meaning they likely didn't actually open the package and just looked at the value on the shipping label and calculated the GST/HST.
The other 50% of the time I've been assessed for full duty/excise tax, GST/HST and the tobacco tax. Even with this large hit you are generally still saving about $10-$15 per tin compared to B&M (in Toronto, not sure about other places).
The way I justify this is by conceptualizing it as "amortizing" the savings across all orders. If say you order 100 tins in a year, and you only have to pay full taxes on 17 of those tins, you are still saving what amounts to thousands over time.