Manesar mein property ka real all-in cost kitna hota hai?

Manesar mein Ambience Group ka project dekh raha hoon, but all-in cost ka calculation samajh nahi aa raha. Builders basic price batate hain, par fir stamp duty, registration, PLC, parking, aur maintenance charges add ho jaate hain. Mera budget ₹1.8 Cr tak hai, 2BHK ke liye. Kya koi bata sakta hai ki yeh hidden costs kitne extra ho sakte hain, especially for a first-time buyer? I'm worried about sudden expenses near possession. Also, construction-linked payment plan better hai ya down payment? Parents bolte hain down payment se interest kam lagta hai, but construction delays ka bhi darr hai. Honestly not sure if the initial savings are worth the risk. Any advice on how to accurately estimate the true all-in cost from day one?