Does negotiation work on Delhi property quotes?

Honestly, this property hunt is confusing. I'm eyeing a 2BHK in Paryavaran Complex, quoted ₹1.8Cr by Goyal Builders. Does price negotiation truly work in Delhi? How much can I realistically knock off? What's the *actual* all-in cost including stamp duty and PLC? Trying to avoid nasty surprises later.