Noida Extension investors: What's the real all-in cost?

Dadri — I'm finally taking the plunge into buying after years of renting. Aradhyam Builders has a few projects catching my eye in Noida Extension. What hidden charges *really* pop up at possession? And for investors, is a construction-linked payment plan always smarter than just a bigger down payment for better ROI? Trying to figure out the true all-in cost here.