Loss Due To Fake Currency Note?

A lady buys goods worth Rs. 200 from a shop. (shopkeeper is selling the goods with zero profit). The lady gives him Rs. 1000 note. The shopkeeper gets the change from the next shop and keeps Rs. 200 for himself and returns Rs. 800 to the lady. Later the shopkeeper of the next shop comes with the Rs. 1000 note saying "duplicate" and takes his money back.
 
How much LOSS did the shopkeeper face?

Find that LOSS here!

Source 

'Cashless' Transaction

What was the tricky? 

The shopkeeper's getting change for Rs.1000 from the next shop is just to confuse you.
He brought Rs.1000 from that shop & gave back Rs.1000. There is no loss or profit from that end. Now he gave genuine Rs.800 & product of Rs.200 to the lady. In return, he got Rs.0 as the Rs.1000 note offered by the lady was fake one. So total loss the shopkeeper faced is of Rs.1000.