The GE has always failed to adjust prices according to the true demand. For example, when the fist of guthix mini-game came out, it quickly became clear that using anchient magics was the best way to win. Unfortunatly, compared to other items, there are very few anchient staffs in the game. Now the law of supply and demand says that when demand goes way up, but supplys stays very low, the price increases. This is the problem with the GE, it increases its prices according to demand, more specificly, when somthing sells. So when there is a very limited amount of an item, the price will not go up enough quickly enough for players. The staffs which I have mentioned, were selling for close to 10x their normal value. This is why people junk trade, and I believe that it is acceptable, because of the GE's inablility to cope with the changes in supply and demand.