Hello,
As a seller it has become clear to me that most new sellers (who bought from me) and some old ones as well know nothing about the Rupee 1 auction.
It is just to make the listings attractive for one.
Secondly, the items get more visibility since Ebay itself regularly features links to such auctions on its homepage.
The exception however is the no reserve auction(s), where there is no unusual swelling of the shipping charges.
Regards