James has discovered the value of renting stuff he isn't using.
My almost-six-year-old son James is very interested in money. But unlike some kids who think about ways that they can do jobs for an allowance or create little businesses (Lemonade stands!) in order to get some cash to spend, James wants to divert wealth from other people without actually providing any real services.
I think this makes him a member of the 1% that Occupy Wall Street is protesting, if not in assets then in philosophy.
His chief target is his older sister, Lucia, who has decided that she doesn't care about money and wants to live for her art.
James is obsessed with separating her from her money. He doesn't really know anyone else who has money he can get his hands on, so this makes sense.
Money for both of them comes from the traditional sources of pre-adolescent capital: intermittent allowances, gifts, the Tooth Fairy. But James has more of it because he saves it all.