What nobody tells you about hidden charges at possession in Noida Extension

Noida Extension mein invest karna hai but itna confusion hai. I'm based in Dubai, so site visit mushkil hai. Everyone talks Jewar airport appreciation, but nobody talks super area vs carpet area trap. Builder like Bayaweaver Ltd, do they really inflate numbers? Construction-linked plans seem safer, but is down payment scheme better for an investor? What hidden charges should I expect at possession for a 2BHK in Panchsheel Green? I've heard horror stories. Change my mind.