Scrap Removal from an Industrial Plant

Well you have a nice little problem, so with out any pictures I am asuming that it is a very labor intense job, time consuming and difficult because of the heights and obstacles you have to go thru to remove the metal that being said the only way to make this job a profitable one is to charge for your labor. And that of a helper this type of job requires to have at least two men on the job at a minimum for the simple reason of safety. We don't think about safety until something unforeseen happens that's why it's called a accident, any way judging from the property owners dicesession he is not in a hurry because he does not want to spend any money to do this demo. You don't want to start this job and realize that you are not making money and have a negative attuitide about this project, so the answer to how much to charge is what you have to decide, your labor plus the helpers labor plus unforeseen expenses
As far as the scrap money goes I would split it with him down the middle this would offset his costs. Good luck hope this helped you.

Can you get a wrecking ball and demo the place. Then chain lift the beams into the can . Two men minimum or you and his men. Too big to do alone. If charges I would bill exspenses only and keep all scrap 100%. But I'm not qualified for a job this scale . Lol I can dream

Doing a large removal at a plant right now, seldom do things go as one would like. As 1956 said two is a must on big jobs for safety.
When I quote a big job, I estimate how much metal I can get out the door per shift, vs the cost of labor and other expenses like grinding wheels, saw blades etc. cost of your roll off bin, or however you intend to get it to the scrap yard.
From what you describe, I would think you need 100% of the scrap value and maybe more to cover all costs. There is no real average for a job like that, each big job like that is different. The one I am currently doing I was told no hurry, now it is a rush, and the lift they thought was available for 4500 lbs is really only 3000 so more labor to break it down. The job is still good but you always have to price it higher for the unknown or you could be working for nothing in the end. Something that looks easy can take half a day if it decides it does not really want to go LOL.
I doubt I would take on a job like that for simply the scrap value.

Congratulations. 200 tons of steel is about $50,000 value.

Your work will involve lifting yourself up and cutting objects located at great height. It also probably involves some dealing with electricity.

It is very time consuming and difficult to do it yourself:

1) You will constantly need to climb up and down and
2) If you get in trouble, no one will know.

If there is 200 tons of steel there, then it is worthwhile to hire a qualified helper, someone who at least knows how to use a torch and lifting equipment.

Also spend time negotiating with scrap yards, you can get a much better price if you can promise 200 tons of steel.