http://en.wikipedia.org/wiki/Yield_management
We wanted to our users to be able see how long a price point is going to remain available. Our hope is that most users will be able to make better decisions about whether to book immediately or to wait a little longer.
With respect to whether the price differences are huge or not, the prices are going to be higher. Travel is an extremely price-sensitive category and India is an extremely price-sensitive market. So, in our opinion, this feature lets users make better decisions.
Since the button seems to be causing some confusion, we'll see what we can do to best improve it.