So you are saying that a block of 100 apartments costs $8...

So you are saying that a block of 100 apartments costs $8 million to build using your estimate of $80000 per apartment ? Have you factored in the cost of the land? professional costs ? council contributions ? etc etc.
Geez, i hope you don't work as an estimator for a construction company because they would surely be broke by now.
Where is this apartment block, India ?