M-sand or manufactured sand is being used as an alternative for natural sand. Natural sand is not replenished at the rate it is being used, hence the manufactured sand is being promoted in its place. They serve as fine aggregate and are superior when compared to the natural sand.
Compared to the natural sand, manufactured sand is cheaper. Manufactured sand costs around Rs 450-Rs 600 per tonne, while the natural sand costs Rs 750-Rs 1200 per tonne.