It doesn’t take a particularly observant Canadian to wander into a midrange, midsize supermarket in an American urban area and instantly be bowled over by the selection. The egg selection, for some reason, is what always tends to flabbergast me — and the low, low, price, if you’re not fancy about it. Then there’s the milk, and the butter and cheese (both domestic and imported) and, further up the fancy chain, things like heritage-breed poultry.