Ready-to-move is the only safe bet in Ghaziabad, fight me

Since January I've been shortlisting flats in Ghaziabad and honestly, the hidden costs are killing me. I'm looking at Sare Crescent ParC, which is ready, versus Celestial Comfort Condominium, still under-construction. Builders advertise one price, then suddenly there's PLC, OC, maintenance advances... it adds up so fast. My parents keep saying under-construction is too risky for possession delays and unexpected total costs. Should I just stick to ready-to-move to avoid all these surprises? I just don't want to get stuck with endless surprises. What's the real total cost of ownership for under-construction projects like Celestial Comfort?