Camouflaged inside a small cloth store in the Janpath market, this has to be one of the easily 'blink and miss' stores that you can find around here unless you plan to shop with your female friend. Separated from the women clothing stall with just a plastic curtain this bookstore has some really crazy deals. Believe me, you won't be able to locate the store if you are new here but try this; from gate 1 of Janpath market try to peep inside the first five women clothing stores, I am sure you will find your way. It's a cramped space, barely enough for a person to be accommodated in. So you will have to wait for your turn.
Regarding the rates, the books are pretty cheap and if you are lucky (like I was!!), you could actually end up buying a book for more than 70% discount in brand new condition. Don't rush yourself while you are in there. Such stores really require your patience, which is always worth. Visit the store and bargain, bargain and bargain. All the best for all the bargaining.
I bought "The Forty Rules of love" by Elif Shafak for INR 150 bucks.