Price negotiation in Gurugram is a myth

My flat possession was in March, and I'm still figuring out the actual total cost. For my 3BHK in Sohna, Conscient bola tha no negotiation. But possession pe aake itne hidden charges mile – utility setup, maintenance advance. Is this common? Gurugram mein kitna negotiation possible hai for a 2.5 Cr property? Should I have pushed harder?