Hi.. As Tata Nano is a low weight car, there is a possibility of the car to miss its control, if you drive it rashly with power steering. Thus, the company doesn't recommend the use of power steering in this car. Thanks,
New Tata Nano with EasyShift is available at Rs. 2 lac (Ex-showroom, Delhi), and the final cost depends on the valuation of your car. So, first get the valuation of your car from authorized Tata dealer, so he can give you a final quote for the new car.