I agree with coldfirezz and Agenator , you need a certain amount of money to be happy , but too much money can have adverse side effects. I like to think of this situation as like pouring water into a glass jug. There is a limit to the amount of happiness that you can get from money alone and having more money then you need to get that amount is useless because it pours over the sides and gets wasted, also if there is far too much money(/water) then the container can break and ruin your happiness.
I would say that happiness is more important than money and that you ultimately get money in the pursuit of happiness, making the process of getting and having money a possible subset of happiness. I would also say that you don't actually need actual money to be happy, but you do need some essential possessions such as food, clothes and somewhere to sleep (eg. Tibeten monks).
Sorry about the weird metaphor. :biggrin: