Panchsheel Enclave purchase: My negotiation reality check

Just got possession of my 3BHK in Panchsheel Enclave last month. Yaar, negotiation ka scene bada different hai. Resale mein I managed to knock off almost 5% from the quoted price. But new projects like Mrigank Enterprise, they barely budge beyond 1-2%. Plus, builder ki hidden charges possession pe shock dete hain. Anyone else got similar tips on negotiation in Delhi?