The troubles that people keep listing as troubles inherent with being in possession of a large sum of money are just as viable as problems to those who aren't rich. How do you ever know who your true friends are? Rich or poor, unless you're a mind reader, that person could be using you one way or the other. That argument seems to be the main one that everyone seems to bring up and yet it's not inherent to those who are rich.
All the other examples of rich people not being happy are just as applicable to those who don't have enough money. Examples of, "I know plenty of people who are rich and they aren't happy," does not equate to money brings unhappiness. People will always have problems as long as they have emotions, this is nothing new. A wise use of large sums of money (and not the "American" way of spending it off as fast as possible until all you see is debt) allows you to have many personal freedoms from most of the man made hinderances developed due to mankind's need for society.
So, if you're going to use rich people as examples of money not bringing happiness, at least mention the reason why they're unhappy and think about whether their unhappiness can only be felt due to being rich. If not, then the problem lies not with large sums of money but with the person.