• Actual plot area and khata is more than what is in the approved site plan

There is a plotted development . The front plot, facing road when measured physically is 300 meters and in Khata also it is 300 meters. But the approved site plan(by BIAPPA) shows only 200 meters.
Looking at th site plan it seems the building margin is inside the plot and the road margin is also inside.
When asked, the builder said that it was excess land that they have used and while we are building or constructing we will have to leave set back area.

Q. Is it legit if the sanction site plan shows less area and actual and khata has more.
Q. Is it worth buying such a plot? The location is promising
Q. What will be the cons of buying this plot 
Q. The builder is calculating the price based on the complete area what would be a valid point in order to negotiate on the pricing.
Q.We asked the builder to calculate price based on only 200 meters but he says if the road gets extended the government gives compensation. How can we calculate the compensation.
Q.Wil ther be issues while selling the land.
Q. How do we calculate a fair price for such land
Q. Any other things that we should be aware of while buying this?

Also the tax is paid on 300 meters.