Bangalore builders hide too many costs

Since last year I've been eyeing 3BHKs around Kaggadasapura, maybe a Prestige project. Upgrading from my 2BHK in Doddanekkundi. Builder quotes for 3BHKs, around 1.6 Cr, seem so firm. I'm trying to figure out if real negotiation is even possible on these prices, ya know? I mean, kitna percent off can you actually expect? Also, trying to map out the *real* all-in cost. PLC, parking, maintenance deposit... sab milake kitna upar jaata hai from the base price? Has anyone faced unexpected charges right before possession? Not sure if OC charges are always clear upfront.