A holiday to Iceland is an excellent idea because everything is expensive so you get through money really quickly and due to the exchange rate, you unless you're really careful, you don't notice how much anything costs. I thought I had a handle on it, but at one point came quite close to unintentionally spending £60 on some salt.
Thankfully, I had another think about the conversion and put it back. I went on to buy something very similar in Lanzarote for 8 euro - flavoured salt, hand dried by artisans in natural sunlight, so no wonder it was so much more expensive in Iceland than Lanzarote.
Might I suggest that for next year's trip, you go to Norway. Perhaps Switzerland the year after?