As a seller, shipping has always been bad and recently gotten worse.
I once posted a Model M in Georgia, on Thursday mid-afternoon, via USPS Priority Mail Flat Rate Game Board box, and it arrived before noon on Saturday in Alaska, for $16. They certainly lost money on that one, and it makes no more sense than charging me the same for Mexico as for Tasmania (yes, I have sold keyboards there!).
But what else are buyers and sellers supposed to do?
No doubt the Canada-US thing is the most ridiculous.