Ghaziabad property search: Negotiating for real?

Budget finalised, loan pre-approved — now stuck on which sector and builder in Ghaziabad. We're a family of four, need a 3BHK, kids' school admission is a priority. My wife wants something safe for the children, maybe near Indirapuram or Vasundhara. We saw a few options, like County Group in Vikram Enclave, but prices seem a bit high, around ₹90L for a 3BHK. Builders bolte hain fixed price, but kya negotiation real mein work karta hai? Kitna percentage tak expect kar sakte hain? Also, super area dikha ke carpet area kam batate hain, iska koi tareeka hai deal karne ka? Or should we just stick to resale property, wahan better negotiation scope hota hai kya? Confused hoon yaar.