I agree with pretty much everything you say Mike. But there's a few things you left out. One is that couriers are of course much faster and more reliable. Our fedex/ups packages are rarely 'caged' nowadays as we've learned how to do the paperwork, so deliveries to the US are next day to major centres or day after mostly otherwise. This compares to a few days up to a few weeks or more, quite unpredictably, by air mail then their local partner, whoever that turns out to be. This may not matter to everyone, but as the supplier we still get criticism when things are late or don't arrive when wanted.

Another factor is 'attrition'. I must admit that I'd failed to notice until now that you're actually in Canada. Sorry. I'm afraid the fact is that we pretty much refuse to send anything of value into Canada that way now, since the rate of 'loss' got to quite ridiculous levels. If a customer insists on Canada Post we ask for a written disclaimer that they will not ask us to replace a missing package. Here's a fact for you - we've had more lost packages in the past year through Canada Post than to the rest of the world (including UK domestic) put together. That may tell you how bad it is. Courier packages very rarely go missing. But the standard postal system is a totally different story, and Canada Post way more than most.

Finally, I can't speak for US-Canada shipments, but I don't think you mentioned the weight limit that applies to air mail. If the package weight exceeds 2kg (c. 4.4 lbs) they just won't take it.

So my basic point is it's not just a question of price, but a bunch of other considerations, such as how soon do you want it, how reliable do you want that schedule to be, and who is going to pick up the tab and knock-on costs if a package goes astray? I don't think it invalidates your point that the more business-orientated companies charge more for the 'same' service of clearing paperwork than the bulk-handling public-facing companies do. But like so many things in life, there's an element of you get what you pay for.