First Delhi home: Fearing hidden costs and bad deals

Been paying rent for 5 years now and honestly, I'm just fed up. Landlord again hiked rent, so finally taking the plunge to buy in Delhi. EMI vs rent math ab samajh aa raha hai. I'm looking at a 2BHK in East of Kailash, maybe a Garg Group project. Price is around ₹2.2Cr. Does price negotiation actually work here? Kitna realistically knock off kar sakte hain? Aur kya kya hidden costs hote hain? Stamp duty, registration ke alawa, possession ke time kuch aur surprise charges toh nahi aate? PLC, parking wagera ka bhi idea chahiye. Not sure if I'm getting fleeced.