for costs and fitting you can contact this guy, i got my cars driver window repaired from him, and he also helped me finding a cheap side view mirror motor.
micheal
0300-2425790.
he would also suggest you what to and where to buy from he can be found at plaza markets opposite, where there are some shops.
My recomendation dont go for the Gas tempered glass. Go for the genuine alike as it has a plastic sheet in between which prevents razor sharp glass to break and fall on the driver. The gas Glass when broken can harm the occupants in the car. at max it would would cost you Rs.5,000