G.B.
What I would do is see what his plans are. There is NO reason to go in 100% right off the start. He can start making small changes and becoming self sufficient in the place he is now.
I have a friend who has less than $100 per month in utilities. She is becoming self sustaining. Her family works and puts money in the bank each month and they spend money to fix things that prohibit them from reaching their goals. Such as putting solar panels on the top of the house and adding a windmill on their property. They research and make long term plans that fit together so one day they can both stop working.
So you need to have a plan. When he has money in the bank and is able to pay his bills without touching his salary then he may not need to work anymore but until that time he has to bring in an income that supports his family.