demolishing old house procedure & cost

Dear sir,

i planned to demolish my old house to construct a new house there.

i spoke to building demolisher in bangalore regarding this,

they are charging 1,10,000 INR for The cost of demolition and debris transportation of your entire building is Rs. 1,10,ooo/- (Rupees one lakh and ten thousand only). If you are giving all the salvage materials like wooden, iron etc.etc. to us than we will minus the cost of materials from the above expenses. If there are wooden doors and windows in your building then the expenses to you is nil, and in this case neither you have to pay us any thing nor we. we will bear the cost of demolition and debris transportation by taking away the salvage items of the building.

Please suggest on this, the charge they are asking is acceptable, reasonable or not?

aslo is this good to sell my doors, windows along with all old salvage materials?

thanks in advance