Investing from Dubai: All-in cost reality check

Been looking from Dubai for almost a year now for an investment flat in Gurgaon. Thinking about a 2BHK around Golf Course Ext. or Sector 51. For builders like Krrish Group, construction-linked payment plan sahi rehta hai ya down payment option better hai for an NRI? I'm worried about total all-in cost – PLC, parking, maintenance. Kya final cost initial quotes se bahut different hota hai? Any advice on managing property remotely and hidden charges?