So initially, they wanted the box returned to them. You query them about a discount, and now they want you to post the item to Hungary. So you take responsibility if it does not arrive there (customs in Hungary have light fingers).

I would send an email to them, stating you will be returning the box to their address (Marco's).  You should also tell them that there is a $22 handling fee at your end. So therefore deduct US$100 from your order. When your order arrives, post their box.