Hidden costs investors only discover after booking?

Spent the whole Sunday researching potential investments in Mohali from Dubai. I'm looking at Satya Merano Greens (around ₹2 Cr+) and Krisumi Waterfall Residences (starting ₹2.79 Cr+). Both are under-construction, which makes me quite concerned about possession timelines. Kya builders ke promised dates pe trust kar sakte hain, especially when I can't do a site inspection myself? Total cost of ownership ka kya scene hai? Builders often quote a base price, but then PLC, stamp duty, registration, and future maintenance charges add up significantly. For a 5-year horizon, which project offers better appreciation potential given the current market in Mohali? Should I be more worried about the under-construction risk with these? Also, legal clarity for NRIs and property management post-possession is a big factor for me.