its an mmo you arent allowed control of your saves it would lead to to much cheating.
you just have to put up with the fact you messed up and make sure you dont do it again.
not that the trade system is a bad idea but it would also lead to to much power in the gamers hands as we could constantly trade items to get what we currenty need instead of making that final raid choice to sink gear in or in the case of red scrips picking the class you want gear for the most.