First-time investor: Delhi negotiation reality check

I completely underestimated how much negotiation matters for a good property deal. Keshav Puram mein AKMS Developer's ka project dekha tha, 2BHK around ₹1.6 Cr bol rahe hain. Builder se kitna discount realistically expect kar sakte hain? Ya secondary market mein negotiate karna zyada easy hai? Pre-launch offers sahi mein value dete hain ya bas hype hai?