I remember a similar bug in the original Asherons Call (amazingly, still running with regular content updates!). Three or four years in, they added a new, very expensive object to the game (a "Pyreal Scarab" for anyone who cares). It cost a lot, so the idea was that people wouldn't be (at that point in the economy) buying many. Now, in Asheron's Call, the world is huge . There are hundreds, if not thousands of vendor…
A nightmare scenario for the developers in both cases.