Seems unlikely mustard-tree.

Sold for £1.85 less 19p commission, less possible listing fees.

The postage costs more then the item, and then there's packaging.

Rose ,I would email them, but didn't you wonder at the price, seems more likely that the Seller doesn't know what he/she is doing.

Have they beeen doing it for long? might be worth a look.

I agree that Free post may have been intrepreted, as free to the Seller, but I really can't see anyone being that naive, and they would soon be put right.  Worth looking into Rose.

I cannot see them stumping up another £1.69, better to give you a refund and forget the item.

Then with your refund you could claim the item from the Royal Mail.

Or..... if the item is worth it you could accept it as a genuine mistake, tell the Seller, and then move on.... it is Chrismas...