Sector 24C residents: Hidden costs and RWA experiences?

Budget finalised, loan pre-approved — now stuck on Sector 24C, Chandigarh. I work in real estate, but buying my own 3BHK here feels different. Builders are always vague about post-possession charges. I'm hearing crazy stories about RWA maintenance and unexpected costs in Sector 24C. Beyond the usual EMI and property tax, what's the actual monthly outflow? Are RWA charges justified for their services? Especially in older societies, not new projects. Anyone faced issues with sudden fee hikes or poor service after moving in? What did you do?