Hidden costs buyers only discover after possession

Okay I'll be honest — deciding on a flat in Noida Extension is tougher than I thought. My kids are growing, so a 3BHK is a must, and safety is key. Brys Buzz is completed, but uska price ₹4.35 Cr se shuru hai. Drona Residency under-construction hai, ₹29.75 L se mil raha hai. Ready-to-move projects like Brys Buzz mein kya hidden costs hote hain jo advertised price mein nahi dikhte? Drona mein UC risk worth it hai kya, considering jab tak possession milega, total cost kitna badh jayega? For a family, is it better to pay more for ready-to-move peace of mind?