Just visited a few resale flats in Sector 35 – confused about the real price.

I'm hearing a lot of mixed signals about negotiation in Faridabad's secondary market. We're looking for a 3BHK in Sector 35, around ₹80L-₹1.2Cr, mostly end-use. Kids ke school admission ka bhi tension hai, so location important hai. Goyal Estate Agency ke new projects bhi dekhe, but resale options pe bhi dhyaan hai. New projects mein toh builders bolte hain fixed price. But resale mein kitna margin hota hai? Kya kisi ko real experience hai ki Sector 35 mein 3BHK ke liye kitna negotiation possible hai? Brokers bolte hain kafi scope hai, but I'm skeptical. Aur hidden costs kya hote hain resale mein? New flat mein toh PLC, OC, electricity charges hote hain. Resale mein kya alag se lagta hai? Stamp duty, registration toh common hai. Broker ki fees kitni hoti hai, aur kya direct owner se deal karna better hai? Any advice?