Thienvv89 I ordered these speakers the last drop. Arrived in Daegu, Korea just about a week ago.
As far as I can tell, I have not had any contact from the customs office about tax and custom fees. Usually the customs official will withhold any items that need to be taxed, and contacts the buyer or importer. The item is not released until the tax has been paid.
So, by the virtue of the speakers being delivered to me, it would seem that there is no tax that need to be paid. Otherwise it's usually 10% including the shipping cost. So around $30~40 extra even if you get taxed.
Hope this helps~