Hidden costs for first-time buyers are easily 20% more than property price.

Okay I'll be honest — I completely underestimated how confusing this process is. I'm checking out Airwil projects in Sector 152, my budget is around ₹78L. But ab samajh nahi aa raha ki hidden costs kitne honge. Stamp duty, registration, interiors... people say 10% extra, but my friends are saying it's way more. Is it like 20-25% over the property price? Aur Airwil ka delivery track record kaisa hai? Under-construction mein kitna risk hai? Any advice on budgeting beyond the flat cost?