Total acquisition cost: The truth for NRI investors

Is it really smarter to buy a 3BHK in Sector 84 via secondary market? I'm based in Dubai, so can't do site visits easily. Looking at Propfolio projects, but worried about hidden costs beyond the quoted price. Brokers here quote ₹1.2Cr for a 3BHK, but what's the *real* all-in cost with stamp duty, PLC, and registration? Also, how much negotiation leverage do you actually get on resale vs. new builds? Need to figure out the total acquisition cost since I'll rely on a POA and property manager.