Greater Noida buying: What hidden costs did you find?

Since last month I've been seriously looking at 2BHKs in Sector 122, maybe even The Hemisphere. Prices around ₹70-80L for a 2BHK feel high, even with Jewar Airport coming up. I'm trying to figure out the real 'all-in' cost. People talk about hidden charges, like unexpected PLC or maintenance deposits at possession. Plus, is going for a pre-launch project actually smarter for an investor to get a better rate, or just riskier? And how much does super area vs carpet area really inflate the price? Any insights would be great.