Inexperienced (euro-pampered) me went to a money exchange place that charged a fee because I know it costs money for them to have random icelandic kronar on hand so that's fair, then they don't need hidden fees right? I also knew the bank from name, it's a household name in my country.
Later at home I checked and I paid out of my ass for the exchange rate, never mind the fee on top...
I thought I was being clever by doing it at departure where you can compare and say no. At the destination airport, you have no choice but to exchange, everyone will need the local currency to pay for things and so I thought it's better to be prepared than potentially be paying the prices of the desperate. Yeah. No.
(A few hours of air time later, I learned that in Iceland you just pay by bank card for everything at iirc 0.3% fee and you don't need to exchange no cash.)