I think my roof contractor overcharged on roof replacement. My friend with same size house used them too but they charged $7000 compared to my $10000.

I am presuming your insurance company paid to have the roof replaced due to an insurance loss. If so, the company would have negotiated the cost with the roofing contractor to be sure the insurance company got the best deal available. Even if the company paid you for the repairs, they would have had to agree to the costs before they would have issued a settlement check to you for the roof.If the roof replacement was not an insurance claim, then you should have obtained alternative bids to replace your roof before accepting the bid from the company who did the repairs. The size of a home is not the only determining factor for costs of roofing. The type of maerials use, the pitch of the roof, fees and permits, etc. It seems too late for you to want to change the contract, but you might call the roofer and advise of your concerns and see if they will agree to a reduction in costs, or explain the reason for the difference. However, this would not be an insurance claim, simply because you feel you were overcharged.