I agree with the comments of our other co forum members, what if the later wants a different product you must prepared a different variety of goods to get ready for your trade and how are things gonna be If the products you are trading will get spoil example meat or other goods that can make the trade not successful if the later is gonna receive a unusable goods that is eliminated in the use of money because it is something universally ready because of its acceptance all over the place its called legal tender.