Hidden costs first-time investors miss in Greater Noida

Budget finalised, loan pre-approved — ab stuck hoon in Techzone IV. Silver Porch Developers mein ek 2BHK dekha hai, quoted price around ₹78L. As a first-time investor, I'm honestly not sure about the *total* cost. Log bolte hain bohot hidden charges aate hain possession ke time pe. Like maintenance advance, society formation, electricity connection, PLC... yeh sab kitna add kar dete hain final bill mein? Also, payment plan ko leke confused hoon. Construction-linked is standard, but does it make sense for an investor? Or should I try to negotiate for something else to manage cash flow better? What's a realistic percentage I should add to the ₹78L for stamp duty, registration, parking, and other charges? Kitna extra budget rakhna padega? Experienced buyers, please share your gyaan. What's the *real* total cost I should budget for in Greater Noida?