Its quite cheap - the one in my Khyber cost me around Rs 180/. It was used kabli - people throw them out all the time for no reason. Check its working by putting it in near boiling water before installing in your car.
If the car is using plain water instead of water/coolant mixture, don't put in the thermostat before properly flushing the cooling system - read this thread: Citric acid powder for radiator flush.
By doing it properly, you will ensure that the engine will cool adequately when used under heavy load conditions with A/C.
If the system is severely rusted out, be prepared to find holes in the radiator and other parts of the cooling system after the flush. I had to have the radiator replaced on my Khyber after performing the flush, because it started leaking. Replace the pipes too if they appear cracked. Your car is a 2013 model, so lets hope that the damage is not too severe.
Make sure the fan is auto, too.
While you are at it, get the water pump and timing belt replaced too - they need to be replaced every 100k km anyways.
A slipping clutch also negatively affects fuel consumption - btw a worn clutch in 4 years indicates this car was used roughly, mostly for short city trips. 8k Rs/. sounds about ok to replace the clutch plate, pressure plate, and throwout bearing, including labour.
