Basically title
Even though RMT is not allowed, the game itself has a lively, constantly renewed economy and MANY people RMTing through various websites and there is a big market for it.
Private servers are constantly launched, and the official game also constantly launches new and event servers and merges the old ones, and there are items being sold for thousands of $ daily
Overall, if the correct crowd (mostly Turkish and German) becomes aware, I can see the Metin2 forum seeing a lot of use