> The likely reason why he can earn this much with a supermarket job is because everyone else has more disposable income, which means it's easier to make products more expensive and to afford to pay higher salaries for such jobs.

Prices also show this. If you want to go get a couple of beers in Oslo you’ll find $10-15 to be normal in central parts of town ($10 average for the city). Nominal wages don’t say much. Purchase power does.