Mohali property hunt: my payment plan dilemma

Mohali Sectors 82-84 — been tracking builder launches here for an investment property. Swaraj Homes ka project dekha, 3BHK around ₹1.8 Cr. Payment plan mein CLPP better hai ya down payment option? From my experience, CLPP gives better leverage for negotiation and cash flow management. But what about hidden charges? Stamp duty, registration ke alawa kya aur costs hain?