Fixed prices from builders are a total farce in Faridabad.

Builders claiming 'fixed price' is a total farce in Faridabad. I'm looking at a 3BHK in Sector 35, maybe with Goyal Estate Agency, and every broker says "no negotiation, sir." But then you hear stories about people getting 5-10% off, especially on higher floors or specific units. My budget is around ₹1.2 Cr for a 3BHK, and even a 5% discount is a huge saving for the total acquisition cost. Is it just me or are they playing games? What's the real room for negotiation, especially for an investor like me trying to maximize ROI? Are there specific tactics that actually work, or is it all about timing and knowing the right person? Also, how much more can I expect beyond the flat price for stamp duty, parking, and all those hidden charges? Feeling totally lost on the real negotiation game here.