theory

By the way, I always worry that I seem argumentative when I ask a lot of questions, but to be clear, that's not the intent! I'm just laying out my current mental picture so people can see where it's wrong and help me update it. I had some existing notions in my head, but they didn't all seem to add up.

No worries, I didn't take it that way, I'm more than happy to answer questions and help comrades flesh out their understanding

That "tariff" gives you more wiggle room to charge above cost.

That's the thing, it's not above cost, it is simply the cost, production and transport are under the same cost structure, got to pay to make it and pay to move it, wages, material and energy are the main costs. In competition-as-war an army with an advantageous position is fair policy

It's not a guarantee of victory, but it's certainly not a war crime, profitability is defined by what you can get away with

I assume it also matters somewhat for brick and mortar stores — a consumer isn't going to drive to the next town just to pay slightly less for bread. But I don't know how big a chunk of profit can be blamed on this. Is it more of a footnote or is it a big deal?

"location, location, location" is a saying in business for a reason, again it's not a guarantee for success, firms that have overwhelming technical development, enormous scale or juicy patents can still overwhelm your location advantage and kick you out of the leading regulator game, but it depends on the sector and frankly energy costs in the wider economy