My confusion about all-in costs in Greater Noida

Since January I've been shortlisting flats in Greater Noida, especially around Phase 2. Sab bolte hain ki brochure price bas starting point hai. I'm trying to figure out the *actual* all-in cost for a 3BHK, say around ₹80L. Matlab, stamp duty, registration, PLC, parking... kitna percent extra lag jaata hai? Suna hai possession ke time pe kuch hidden charges bhi aate hain, like maintenance advance ya club membership. ABA Corp projects mein bhi aisa hota hai kya? Koi bata sakta hai ki kya-kya surprise costs expect karun? Bahut tension hai ki budget se bahar na nikal jaaye.