Gurugram property: Are my negotiation tactics outdated?

I've bought a few properties, but Gurugram's current market has me questioning my usual negotiation playbook. I'm looking at a 3BHK in Ganga Group's project in Sector 35 Sohna, quoted around ₹1.8 Cr. From my experience, new launch pricing often has a 5-7% buffer for negotiation, but builders here seem to hold firm. I'm weighing a construction-linked plan versus a 20% down payment for better leverage. Is a 3-5% price reduction realistic on a new project, or am I better off pushing for a waiver on PLC or club charges instead? What about the all-in cost calculation? Stamp duty, registration, parking, and especially the 'hidden' possession costs can add another 10-12% easily. What's been your recent experience with total acquisition costs and effective negotiation in this market?