Lemonade Stand Economics

Some people will wonder why anyone bothered to explain such a simple concept as "profits". Well, I once invented a board game called "Tax Wars". It was like Monopoly with an added element of "screw you opponent". Players could submit bills to Congress to tax property or money (whatever your opponent was holding more of than you). Playing it with some kids one day, a child wanted to buy gold when he landed on the Gold Exchange square. Wait, I advised him, Gold is currently at the top of its price range. You want to buy it when its low and sell it when its high. The difference is called "profit". The kid looked at me earnestly and asked, "Is that legal?" Yeah, I should go try to market that game again. America needs it.