Gurugram investors: What hidden costs did you face?

Did some research on Navraj projects in Sector 112 last night, specifically around Dwarka Expressway completion. I'm based in Dubai, so can't do a site inspection myself, which makes me extra cautious about the total cost. I'm looking for an investment 3BHK, maybe ₹2-3 Cr range. My main concern is hidden charges. Beyond stamp duty, registration, and PLC, what else pops up closer to possession or even after? Are there any unexpected maintenance corpuses or club charges that hit hard? I'm worried about getting a surprise bill when I'm not even there to check. Also, for someone relying on power of attorney and a property manager, how do you ensure transparency with all these costs? Is it common for builders to spring extra charges on NRIs? Any advice on negotiating these or what to look out for in the agreement? Thanks!