Just stating my opinion on this.
As much I would love a trade system, it just wouldn't work. Rich players could buy out the economy and hold on to their rares to increase the value. Players with more money (in real life) would also have an unfair advantage buying massive amounts of gralats to purchase items to trade. If we added it, people would start to complain about having it and whine for it to be removed. It's happened twice on Era PC, and led to a server reset. Plus, Real World Trading would start to become an issue. It just wouldn't work in Graal.
Maybe player hosted auctions or something would work better, but its probably just best to keep it as is or remove dropping as a whole.