When you want to sell your old books, the waste paper dealer will pay you by weight. When you want to buy a second hand book on the pavement you will have to pay 50% of the price of the book. In other words, if you want to sell a book which you bought for Rs.500 and the weight of the book is 500 grams the dealer will give you Rs3 @ Rs.6 per kilo. When you by this book second hand on the pavement you will have to pay 50% of the price i.e. Rs.250 These pavements sellers make fantastic profit. .
May be they have to bribe the police and the corporation officials whose duty is to keep the pavement free for the pedestrians to walk.