@Moho we have tried to do something of that nature, but it is hard to maintain. There is an Elvenar chat available, and people would post on there when they were going to put up trades so that others could grab them before the "market manipulators" did.
This is just general impression, but it seems to be getting worse. It used to be just a couple of folks doing this like it's their job and now I see pages of it. There is a fellowship in particular who must train their members in this sort of behavior. <sigh>