A question that a lot of people have asked me, and I many! How much is enough? What is the magic 'x' amount of money/assets/material stuff that if one owns, one does not desire anymore?
Clearly, unlike the ultimate answer to the question of life, the universe and everything, the answer is not 'forty two' or any other number. It cannot be, is my personal experience. When I was an engineering student, I used to think a salary of 40k per month was the end-all of most dreams. Then the investment banks came in and spoiled us with dreams of many zeros at the end of some obscene number of dollars in annual compensation. The bar kept rising higher and higher (as indeed did inflation - of houses, cars, food, everything else).
My buddy, who probably earns in fractions of millions of USD in Hong Kong, has also undergone the same phenomena. Last when we spoke of such things, he said he would be happy with something that gave him risk free income of some x amount. Needless to say, he has surpassed that target quite some time ago, but is still on the hunt for more mammon. He sometimes feels unhappy at his pace of life, but on the whole the feeling of being on-the-move energizes him.
Of course, money is not the only thing most people desire. I always like to read the stupid celebrity interviews where the subject is asked to rate by order of priority - fame, money and power. Invariably fame and power get higher billings than money. This is true for a lot of us as well. Money is just a way of keeping score!
The answer to the question therefore, in my mind, is truly what you limit yourself to - and also what you can aspire to. It is a bit like Maslow's heirarchy - when one target is met, one automatically moves to the next one, because without targets there is only boredom. Rare (and very lucky) is the person who has enough! How does this mythical dude entertain himself??