Hidden charges and negotiation: What Bengaluru builders don't tell you

Visited Aratt's project in Kachamaranahalli last weekend. My wife and I are looking to downsize since the kids have moved out, don't need such a big place anymore. Saw a nice 2BHK, they quoted around ₹1.2 Cr. But honestly, I'm not sure what the true 'all-in' cost will be. Is that just the base price? What about stamp duty, registration, PLC, parking? Do these add up significantly? I'm worried about hidden charges that only pop up at possession. Has anyone bought from Aratt or similar builders recently? How much can one realistically negotiate on the final price in Bengaluru? Should I push for a spot discount or is that not really a thing anymore? Just want something manageable without surprise costs.