Question : What day in the next four weeks has the best fares?
Answer : Since low prices are preferred, look at Mar 5th. As of Feb 27th, it's showing the cheapest ticket sales at $4,094. That is 8% below the average price for this route, so you can spend that extra cash on an adventure in Busan.
Question : How much should a trip from Reykjavik (KEF) to Busan (PUS) cost?
Answer : Ranging from $3,909 to $5,041, prices for KEF to PUS fluctuate much less than most routes from Iceland. Prices tend to be lower the further out you book.
Question : How long do most people visit Busan?
Answer : Of course you're not most people, but if you were, you'd stay roughly eight days.
Question : Is price more important than specific travel days for you?
Answer : Sunday is your cheapest day to fly in March. Having flexibility in your travel plans means you can save more, so be sure to plan ahead when possible.