They claim that money can’t buy happiness, and they mean that material possessions can’t make a person happy which is true.
But it isn't true for the reason that modern moralists want us to believe. It’s not because money or possessions are evil, or that they poisons us “spiritually” making it easier for “a camel to fit through the eye of a needle than for a rich man to enter the kingdom of heaven”, nor is it because they somehow create inequality, or oppresses the guy that doesn’t have quite as much.
No, the actual reason is that money, or any other possession for that matter, is not the requisite end, though it can be a means to the end (happiness) if used properly. If one treats money (or any similar good) as the end product of their life they are missing the point of that life.
If you buy a Harley Davidson for the prestige and believe that it will bring you the attention and the adoration of a certain crowd or group and therefore it will make you happy, your happiness will be a ghost; gone as soon as you step off the machine. If on the other hand you buy the Harley because you desire to ride and enjoy the particular feel of the scooter, that your value is in the quality of its craftsmanship its originality and of course the riding itself, then every time you ride you will be happy, and that happiness will spill over into other parts of your life.
The point is that life isn’t about the accumulation of physical wealth or goods. He who dies with the most toys may or may not be a winner, but it isn’t because of the toys.
The winner is the man who achieves his values, who lives by those values. But those values aren’t necessarily possessions; they are the actualization of concepts and reason, of moral and ethical choices. They are all the parts, pieces, premises and pleasures that further our lives.