It simply wouldn't be doable with the design or the current market board. This only woks in games like gw2 because of the way the board is designed. Allowing you to buy the cheapest in specific amounts regardless of stack size. The sheer size of it keeps re-sellers at bay and the design of it encourages same price listing or small undercuts. 1 coin.

RMT is not going to be any worse or better with this kind of system. RMT will find a way. they always do.