Ghaziabad builder quotes are never the final price

Did a site visit to Universal Infratech's project near Madhopura last Saturday. The 3BHK units they're pushing look decent, around ₹90L for a 1500 sqft super area. I'm currently in a 2BHK in Vaishali and thinking of upgrading, but I'm really trying to nail down the *total* cost of acquisition here. Builders always quote a base price, but what about stamp duty, registration, PLC, parking, club membership, all those 'extras'? It feels like a lot gets added on top. I'm trying to figure out the real premium I'll pay. For investors, these hidden charges can kill your ROI, you know? Is there a general rule of thumb for how much these extras add up to, percentage-wise, over the quoted price in Ghaziabad? I've heard some builders in Crossings Republik add 15-20% easily. What's been your experience with Universal or similar projects around the Delhi-Meerut Expressway corridor? Trying to avoid nasty surprises at possession.