Noida mein payment plans ka game kya hai?

Fed up of renting for 8 years now, finally taking the plunge in Noida. Everyone talks about property price, but nobody really breaks down the payment plan leverage. Builders push construction-linked plans, saying it's safer. But isn't a down payment + loan better for an investor? Matlab, you lock in the price, EMI starts, but you save on all those PLC and floor-rise charges that keep adding up till possession. I'm looking at something around Sector 112, maybe Oasis Buildmart India Pvt Ltd. My budget is ₹1.2Cr for a 3BHK. But the 'all-in' cost, with stamp duty, registration, parking, plus interiors, feels like a black hole. Is there a hidden cost percentage one should always factor in? Change my mind if I'm wrong about CLP.