The alcohol retail system in Iceland is quite similar to what you find in Sweden, Finland and Norway, with a state monopoly running the shops. Iceland and Sweden are the strictest, where what you would call everyday beers also have to be sold through these shops.
This is obviously a hassle for the Icelandic beer drinkers, though a casual observation of the Reykjavik street scene on a Saturday evening shows that the teenagers get enough of the cheapest canned drinks there as everywhere else.
For a foreigner on a whistle-stop tour, however, it means that there is one shop within one shopping mall that carries all Icelandic beers.
A bright and airy shop, very similar to Systembolaget stores. Maybe 25 Icelandic beers, half of them from micros, plus imports from Denmark, Germany,, the Netherlands, Belgium.. – the usual suspects. The only exotic among the imports were six beers from the Faroe Islands.
A decent selection for a one time visitor, pretty thin if the alternatives are a few hours away by plane. Inexpensive as long as the Icelandic currency stays at its present level.