Korea is the most expensive shard on this site and the honest reason is supply, not prestige. Korean accounts cannot be created in bulk the way EUNE or Turkish accounts can — every one we list is sourced individually, which is why the price sits well above NA and why the stock counters here read in single digits rather than dozens.
What you are buying is the highest-quality solo queue in the game. The Korean ladder is where the professional meta actually gets worked out, and playing there for a month will teach you more about lane discipline and wave management than a season anywhere else. It will also be humbling. Come in expecting to lose games you would have won at home, and buy the fresh-MMR tiers so your placements reflect your play rather than a stranger's.
Note — KR requires identity-verified sourcing, which is why the price sits well above NA.