You’re disregarding training, labor, and the intangibles of culture and tradition. Those things should be cheaper, but in America we’ve basically all but destroyed bakery artisanship at the altar of capitalist efficiency, so its rarity has now made its products more expensive. Cheese is in a slightly better position, but only barely, and very regionally-dependent (Wisconsin and Oregon, for example).

So yeah, I don’t disagree, it should be about half the price if we had better artisan programs in the US. But I don’t think wonder bread and Kraft singles should set the bar for grilled cheese pricing.