It's because of the insane taxes and government-owned monopoly on sales. But you'll still find apologists in this thread saying with a straight face that "it's actually reasonably priced" which is objectively false.

It's really only because of the taxes. Vinmonopolet prices are marked up by 10.4 NOK per liter plus 21% of the purchase price excluding taxes and duties up to a maximum of 250kr per item. Of course, this means they can't have loss-leaders, but at the same time, you can end up with very good deals on expensive drinks relative to many other countries.

Of course I would love to see Norway lower some of it's sin taxes - these mostly only hurt poor people.