Hidden charges builders don't tell you upfront in Bengaluru

My wife and I desperately need a 3BHK for our growing family, kids’ school admissions are a huge factor. We checked out Ambika Developers in Subramanyapura last weekend, project looks decent, seems safe for the children. But yaar, the quoted price for a 3BHK is quite high, around ₹1.4 Cr. Is that the actual 'all-in' cost? They mentioned stamp duty, registration, parking separately, but what about other hidden charges? Matlab, is there a PLC or floor-rise premium they'll spring on us later? Also, negotiation, does it even work in Bengaluru? Kitna realistically can one bargain down? Don't want any surprises closer to possession, especially with school fees coming up.