I think it's one thing to pull an into the wild and say that you're living without the influence of money in your life, but it is another thing entirely to live off of the gifts of others including housesitting etc. and to say you live without the influence of money. Also, to accept medicine as a gift or really anything else as a gift has an opportunity cost associated with it. If you don't pay for something that someone else would conceivably like to have, it raises the cost of that item for others. There's no such thing as a free lunch, for the most part, that is true.
But if that person gave that item up in the sense of throwing it out or giving it away freely, wouldn't anyone then have the same right to that and so the cost would be the same for everyone?
On vacation with family, but here's a good start: https://www.google.com/search?q=opportunity+cost&ie=UTF-...