3: Lack of a min and max price system, which forces players to sell items at the real value.
As people say after all of your whine posts, the "real value" of an item is what someone will pay for it. You think the price of something is too high? Don't buy it then. If everyone else feels the same way, then the seller will be forced to lower the price. But most of those times those items do sell, which means you're just too cheap.
The GTN isn't a charity function. There are planetary commendations for that.
Also, why on earth would anyone ever sell an item at cost? It would be much less hassle to just sell the materials if there wasn't a profit involved.