Gurgaon upgrade: Total cost mein confused hoon

Visited projects on Golf Course Extension Road, looking to upgrade from my 2BHK. Prices for 3BHKs are crazy. Gurgaon mein stamp duty aur registration costs kitne hote hain exactly? Is 8-10% standard? Also, secondary market deals vs new properties, which is better for overall cost? Sanjay Arora Associates ke projects dekhe par total cost ka idea nahi mil raha.