Bag of the Wandering Merchant

This bag has the ability to turn items into gold and to expand to fit said items. When an item is placed inside the bag it disappears turning into gold pieces equal to half of the items original price. The size of the item determines the time it takes to place it in the bag as the bag must expand to fit said item. An item of tiny size or smaller takes a free action to place inside(1ft by 1ft), size small takes a bonus action (3ft by 3ft), size medium takes an action (5ft by 5ft), size large 1 min (10ft by 10ft), and any size above large is impossible. The bag will not accept any organic items, nor magic due to the varying costs the magic items have, if someone tries to put said item in the bag it will close its mouth shut before the said item is placed in, only opening when the rejected item is pulled away.