I think that a person should be atleast Platinum / Diamond league on Starcraft 2 Battlenet ladder before deciding to get a sc2 Korean account.
Why?
1. You get more confidence if you're above the Gold level and it will show in your game.
If you’re Gold league in Korea, it probably means that you’re at least in diamond league or Plat on other servers.
2. Korean SC2 players are so well-versed. It's where you see Bronze players micro like they were Slayers Boxer or Marine King Prime.
3. Social reasons - unless you speak Korean, you’re missing out on the chance to make friends and training partners on your native server.
So if you're planning to purchase a Korean SC2 account, go get it from the official Starcraft 2 CD key supplier - RTS Dealer.
RTSDealer.com is the only English website that sells cheap Korean SC2 keys legally.