itemdump is a dump account, and items in it will not be returned to circulation. itemdump exists because deleting items is more of a pain than it's worth. Items in itemdump are not guaranteed to work right, or even at all. As a result, items that have been sent to itemdump have generally been sent with the assumption that they will never be returned to the economy. In short, those items are gone, and will not be auctioned off.