Secondary market 3BHKs in Gurgaon — are they a better deal?

My lease ends in 4 months and I still haven't figured this out. We're looking for a 3BHK around Golf Course Extension or Dwarka Expressway, mainly for the kids' school admissions and a safer neighbourhood. My wife's priority is a good community. We've been checking out new projects, but the prices for a good 3BHK (like 1.8 Cr+ in M3M or Emaar) are just... wow. I'm wondering about the secondary market. Can you actually negotiate more on resale flats compared to new builder projects? I heard from a friend that Experion Developers' new launches have very little room for negotiation, maybe 1-2% max. But with a resale, especially if someone needs to sell fast, could we push for 5-7% off the asking price? What are your experiences? Is the stamp duty calculation different for resale? Any tips for finding good secondary market deals in areas like Sector 65 or 102? Hope this helps someone else too.