Ghaziabad negotiation: What's the real discount possible?

Has anyone actually managed to get a good discount from builders in Ghaziabad recently? I'm in real estate myself, but buying for my family in Shakti Khand feels different. Looking at a 3BHK, maybe KDP Buildwell or similar, around ₹80-90L. I know the super area vs carpet area games, but how much can one realistically negotiate on the base price? Sales teams always say prices are fixed. Is that true for Ghaziabad, or can we push for 5-10% off the record? I'm worried about hidden charges that pop up late, like unexpected PLC or OC at possession. What should I look out for beyond stamp duty and registration? Any experiences with getting these charges waived or reduced? Or are there specific clauses to watch for in the agreement? Just trying to avoid those last-minute shocks.