When an Indian who earns in Rs travels to a foreign country the cost of travel is huge in terms of what he can get for the same in India. India expects foreigners to pay as much as they are used to paying for similar services. In India they anyway spend very little as the cost of living in most places in India is dirt cheap when compared to international cost. A loaf of bread in India costs $ 0.20. A small portion of butter $ 0.1 and a bottle of jam $ 1.
A tourist to a developed country spends 3x times more than in India even if he lives in India in a posh hotels and spends lavishly. Indians spend a lot of money when they travel abroad for budget hotels and average service. So it is apt to have a differential. The way the western countries have placed their currency, it should not benefit the same people all the time.