Gurgaon new projects hide too many charges.

My kids have moved out and we're selling our big family home. We need a smaller 2BHK in Gurgaon, maybe Sector 45, for easier hospital access. Looking at new projects from builders like Paramount Associates and some resale flats. Does negotiation even work on new properties? Builders quote ₹1.8 Cr for a 2BHK, but is that the final price or can I realistically knock off 5-10%? What about hidden charges? Stamp duty, registration, I know those, but are there other surprises at possession? PLC, parking, maintenance... I'm honestly not sure if the 'all-in' cost is ever transparent. Has anyone managed good discounts recently? Or are secondary market deals better for negotiation? We just want something manageable. Any advice on avoiding last-minute shocks?