Bengaluru property mein negotiation kitna possible hai?

Visited a couple of potential investment spots in Koramangala last weekend, checking out Columbia Pacific Communities. Just moved into my new 3BHK near Sarjapur Road last month, possession was in March, aur abhi bhi lagta hai bahut saari cheezein miss out kar di. My first-hand experience with negotiation in Bengaluru was pretty tough. Builder ne hardly 1.5-2% discount diya, woh bhi after so much pushing. Is this normal for the current market? Heard some people say pre-launch pricing isn't always a huge discount compared to later. Kisi ko construction-linked payment plan se fayda hua hai ya down payment better option tha? Honestly not sure how much one can realistically negotiate on a 1.5 Cr flat.