Greater Noida investor play: Pre-launch deals vs payment plans – what's the real advantage?

Under-construction projects mein value milna abhi bhi possible hai Greater Noida mein, I feel. Just moved into my Rising Group flat in Sector 97 last month. Pre-launch deals kaafi attractive lagte hain, but actual discount kitna milta hai, not sure. Construction-linked payment plan vs down payment mein konsa option smarter hai for an investor? Kya lagta hai, where can we get better negotiation?