Business Basics 101:
Figure cost on all materials and any other costs, like fuel and paperwork, fees, parking, insurance.
Figure how long it is going to take you and maybe add some time for the unseen time robbers. Now you have an idea what labor is going to cost you.
Now you know your out of pocket expences.
What do you need as a living wage??? add that in.
What margins does your business need to stay open, as your wallet is not the businesses wallet, and the business needs money to make money.
All that added up and divided by the sq.ft and you have your price. Any less and you may be filing bankruptcy sooner then you think.
Are you sure you've contracted before????

If your business is trying to charge what another business is charging, good luck on that. That is Business suicide, 304