Norwegian in Argentine pesos
 

I noticed that you can change the currency you pay in, by going to the Norwegian website in different countries. For whatever reason, the prices sometimes don't reflect the actual exchange rates even allowing for a few days to catch up.

For one flight I'm looking at (intra-Europe), the price is GBP 54 on the UK site, but based on the exchange rate right now, it is £60 worth of euros on the Irish site, £59 worth of NOK on the Norwegian site, £49 on the Swedish site, and £45 on the Argentinian site.

For another flight, it's GBP 50 on the UK site and around £48-49 in EUR, USD, CAD, SGD, DKK, NOK and PLN, but £43 in SEK and £40 in ARS.

Booking in SEK should be safe enough and will represent some savings over booking in GBP even accounting for tomorrow's Amex exchange rate being 0.5-1% off the rate I used for my comparisons, unless the pound suddenly drops by 10% overnight.

However I wonder whether it would be wise to book in ARS which seems to be cheapest for all my searches. From what I know, there is no longer any different official and parallel rates, and the peso is continually going down (like the Turkish lira) so would be incredibly unlucky if I ended up paying more than booking in GBP - but would there be any other repercussions?

The only repercussions that you may have would be if you end up getting the flight refunded (does Norwegian ever issue refunds?).