Hidden charges are a Noida Extension scam

What's with the insane final charges from builders like Gaursons or ACE in Noida Extension? My friend just got hit with huge PLC and maintenance deposits at possession for his 3BHK, way more than discussed. This was in Sector 150. Is this standard practice now, or are some builders like Godrej or ATS more transparent with their costs for projects near Jewar Airport? Honestly, the RERA compliance feels like a joke when these things pop up. What did others do when facing such last-minute demands?