Hidden costs and site visit tricks for first-timers in Gurugram

Since January I've been shortlisting flats in Gurugram, mostly around Sector 84. I'm looking at a project by Whiteland Corporation and honestly, I'm super nervous about all the hidden costs. What did you guys actually budget for beyond the property price? Like stamp duty, interiors, and PLC – I heard it adds up fast, sometimes 15-20% extra. My budget is around ₹78L for a 2BHK, but I'm not sure if that's enough after everything. Also, for site visits, what are the absolute must-check things builders won't volunteer? Not just the layout, but like, water pressure, mobile network strength, or even sun direction? My first time buying, so I'm trying to avoid any surprises. Any practical tips would be super helpful.