Shri Nilyam's low price hides hidden costs?

Finally taking the plunge and buying in Noida! Shri Nilyam Dream Homez looks cheap, but is it *really*? What's the catch? Panchsheel Pratistha is ready to move, but pricier. Is paying extra for immediate possession worth it vs the risk of under-construction projects? Has anyone compared total cost including hidden charges?