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

So I have been asked by the owner of an apartment building that is being gutted and revamped how much I would charge to remove all the piping from the existing configuration. The building is in Detroit and is probably 100 years old. It had steam heat and they want me to remove all plumbing including bathtubs and sinks. I already took out the boiler and extremely large hot water tank today!



And yes, I am going to charge for this, I certainly am not going to do it for the scrap value alone.

Any feedback would be greatly appreciated!