Gutting a business for pipes...how much to charge?

I would figure how many hours and how many guys per room, how much you want to make per hour to cover expenses. And then x by the amount of rooms. consider if there will be electricity in the building or will you need battery tools or lights, or setup a temp panel. Consider the weight of the material when you remove it if your 8 floors up with a cast iron stack running all the way to the roof from the basement and to all the rooms it's going to need to be cut into small sections that are lift able which is probably a day of labor in itself. Also consider pipes running in or under floor joists, trusses, and in areas that aren't demoed out that will be hard to access. And consider a way of getting the material out such as 8 flights of stairs vs an elevator vs a trash chute, also how you will move the material out and any permits you may need for a job of this size. Also any new tools you may need for the job can be added into your bid