Ghaziabad property: What's a realistic discount?

Okay I'll be honest — I completely underestimated how confusing this process is. Planning to invest in Ghaziabad, maybe Indraprashtha Yojna. Eldeco Group ke projects mein price negotiation kitna realistic hai? Log bolte hain 5-10% tak milta hai. Aur all-in cost mein hidden charges jaise PLC ya OC kitna add karte hain? Total acquisition cost kaise calculate karoon?