Greater Noida 2BHK costs: what am I missing?

Okay, I'll be honest – I'm completely fed up of renting, landlord raised rent again. Finally taking the plunge for a 2BHK in Greater Noida, maybe Amrapali Leisure Valley or something by Earthcon Universal. My biggest worry is the 'all-in' cost. The base price looks okay, but then there's stamp duty, registration, PLC, parking... it just keeps adding up. How much should I realistically budget *beyond* the quoted price? Also, what's the deal with super area vs carpet area? Are builders transparent about this, or is it a trap? Don't want to pay for space I won't use. Any hidden charges to watch out for at possession? Want to avoid nasty surprises.