Noida Extension mein property ke hidden charges kitne hote hain?

Okay, I'll be honest — I completely underestimated how many hidden costs there are beyond the base price. I'm looking at a 2BHK in Block A, Noida Extension, maybe from Bricks And Dreams, budget around ₹75L. But then there's stamp duty, registration, PLC, parking, IFMS, maintenance deposits... it just keeps adding up. My parents keep saying 'final cost poochho,' but builder reps seem to gloss over these. What are the biggest surprise charges you guys faced at the time of possession? And is there a thumb rule for how much extra to keep aside, like 15-20% over the property price? Honestly, I had no idea it'd be this complex. Need advice before I commit to anything. Koi shortcuts ya tips hain to batao.