When you go through customs and enter duty free, there is obviously no return to the check in desks etc... (including the airport car park), so...... why on earth do they sell huge televisions and other massive items in the duty free shops, you cant exactly take the TV onto the plane as hand luggage and you cannot take it back to the baggage desks because you've already gone through customs, what are you supposed to do with it???
I would guess you arrange delivery ?
Not that I've done so myself. Duty free is not profit free. The amount you save always seems more than it tunrs out to be when you check the Net after the holiday. Someone does well pocketing the difference.