Current construction cost for Marble and Vitrified flooring

Hello Guys,

Just wondering if any one can help......We are contructing a house in Pune and have hired a contractor for Marble and Vitrified flooring work. The flooring area to be covered by Marble and Vitrified tiles is around 42 sq m ( 452 sq ft) each. We asked the contractor that the price range of the Marble shuold be within Rs 50 to 60 per sq ft and Vitrified tiles to be within Rs 65-70 per sq ft. The contractor is charging the following rates ( Materials + labor)

• Marbel Flooring: Rs 1200 per sq m  for flooring , Rs 1400 for Skirting
• Vitrified Flooring: Rs 1800 per sq m for flooring, Rs 1900 for Skirting
• Supervision Charge: 18 %

Here are my questions:

• It does not sound to me but are these rates resonable or exorbitant?
• Is it customary to charge 18% supervision?

Will very much appreciate it if some one can reply.....Thanks again for the help in advance

Regards

Rajendra