I have placed orders with "what the book". You can get free shipping within Korea if the order is above W15 000. Also, you need to have a Korean person's phone number, when you place the order,so that they can varify your address or call (in case)to get the directions correct to your doorstep.
You'll have to log in and create an account.Once you have placed an order, they display an amount of time for delivary. There's a "fast books" section also, where you can order and receive the books the next day or within 2~3 days.Yes, some books do have to come from the States and the usual wait is 18 days.The sale section is also great.I highly recommend this place,if you don't have a credit card in Korea.
ps.can't wait for Harry Potter 6..about 135 days left(not sure about the days)