Gurugram property buyers: How do you deal with hidden costs and delays?

Visited a M3M project on Golf Course Extension Road last weekend, and honestly, the sales pitch was glossy. But my experience with an Emaar project near Dwarka Expressway was a nightmare. Possession mein 2 saal ka delay, aur phir maintenance charges plus PLC itne badh gaye. Matlab, pre-launch mein jo price quote karte hain, final tak double ho jaata hai. Does anyone actually trust these timelines and hidden costs anymore? Especially for a 3BHK around ₹3 Cr? I'm debating under-construction vs ready-to-move in Gurugram. UC horror stories make me pause. Kaise calculate karein ki final cost kya hoga?