Builders ka 'no negotiation' policy is pure drama

Budget finalised, loan pre-approved — now stuck on which sector. I work in real estate but buying for myself is different yaar. JM Housing Sector 80 mein kuch options dekhe hain. Builders bolte hain no negotiation, but I know spot discount milta hai. Kitna realistically expect kar sakte hain? Aur super area vs carpet area ka game toh har jagah hai hi, isme kaise safe rahein?