Gurugram builders hide too many costs.

I thought being a broker, I knew Gurugram real estate inside out. But buying my own 3BHK near Sector 85, maybe a Vatika project, has been eye-opening. Builders ka super area vs carpet area game aur hidden charges, yaar. What's the realistic all-in cost for a 3BHK? How do you guys avoid possession ke time pe new surprises?