The GC isn't running a charity and neither should you be.So if you told them or had a contract with them to do it at cost (without any stipulation as to what cost truly is) you would probably be able to argue that you should get the actual true expenses plus some admin fees and your time on the job without profit. 

The question you need to ask yourself is, I am I running a business, or a charity?

You're in a business world, not a charity 

I am currently involved in a charity out here in Denver that helps those in financial crisis.  

I wouldn't have done much worse if I gave them to a charity.

I really think the " QUESTION" is do you raise rents... if you do you keep up with inflation, if you don't your a charity,, Does the gas station at the corner care if you drive a beater or a new car??

Landlords planned for a rainy day, but they didn't plan for the federal government to come in and tell them that their business is now a charity whether they like it or not.

He is not a charity! 

@John ReelIf this potential mentor is genuinely doing well at their business, their goal for this meeting is to find how you can contribute to that business.Unless this mentorship is a charity (<1% chance) you will have to add value to this relationship.Ask questions such as.What are we in the business of doing?

So I stepped in we formed a JV and I bought them all so that he/we could resell.. cost him some money as of course I am not running a charity.. but it kept him in business once he got on the DRE radar. :) I suspect in SC my type of services will now become common place.