If the valued exceeds 13K... And 13K ores are already have been bought it just simply close the grand exchange and go to blast furnace without waiting for the offer to finish.... It can be collected next time he came again for restocking...If the inventory contains Ores and Coal... Close Grand Exchange and contiunue.... There is one more option that if the value exceeds 13K it should buy 13K ores not more than that..Thanks Man