Gurugram mein real negotiation happens only in resale.

Gurugram mein builder se real negotiation kitni possible hai? I'm eyeing a 2BHK near Sector 111, Suncity Projects type. Builders ka spot discount toh I know is mostly for show, maybe 1-2% max. Secondary market mein better deal milti hai kya, especially for properties jo 2-3 saal old hain? Aur possession ke time kya hidden charges aate hain, like IFMS or club membership jo pehle nahi batate? I know the game, but personal buy mein extra careful. Any tricks?