Noida property buyers, what hidden costs did you face?

Thinking of downsizing now that kids have moved out. Noida mein dekh raha hu flats, but confused about builders. Supertech ka naam suna hai, but on-time delivery ka kya scene hai? Heard some bad stories. Also, log bolte hain possession ke time pe PLC aur EDC jaise charges nikalte hain. Is it true? My budget is tight because resale se hi nikalna hai sab. So, want to avoid surprises. Amrapali ke bare mein bhi suna tha kuch problems hai. Any real experiences with hidden costs from different builders in Noida? Should I be worried about RERA compliance bhi? Help a senior citizen out! Hope this helps someone else too.