Rajkot flat buyers, what hidden costs surprised you?

Honestly, the 'all-in' cost for a flat in Rajkot is never what they quote initially. Kids moved out, so my wife and I need a smaller 2BHK around Mota Mava. Selling our big place. Builders like Ansal API quote base prices. What hidden charges truly appear? Beyond stamp duty and PLC, what extra costs like maintenance deposits or utility fees should I expect?