Yamuna Vihar 2BHK: all-in costs and payment plans confusing

Yamuna Vihar keeps coming up every time I shortlist something. Kids have moved out, so we're selling our large house and need a manageable 2BHK, around ₹1.8-2Cr. Mehta Properties has a few places. I'm really trying to get a handle on the *true* all-in cost. It's never just the base price, is it? Stamp duty, registration, parking, even floor-rise premium for a decent view… it piles on. Honestly, not sure how much extra to budget for all that. And this super area vs carpet area business, does it really inflate the price that much? We want a compact place, don't want to pay for wasted space. Any advice on payment plans too, with funds from our resale?