Definitional problems abound in this discussion.
Is happiness something like the sum of satiety, security, comfort, and ease? Because those are all pretty linearly correlated to money, at least until a certain stratospheric wealth is attained where more money can't buy more. These are all hedonic values.
An opposite view is that happiness is found in detachment from hedonic pursuits. Indifference to satiety, security, comfort and ease: that's happiness, according to a couple billion people at least in theory.
Then there's the grand adventure view. The stakes of life are on a different order from either satiety or indifference to satiety. Life is not ultimately a mere accumulation of moments consisting of positive or negative experiences, with an abrupt and meaningless endpoint. Rather, there's an ultimate good to be pursued in partial and mortal ways, tending towards spiritual wholeness and immortality. To spend one's life seeking that good and helping one's friends and family to seek it is happiness - whatever hardships come.
Having known people who are/were guided by this last view, I'm partial to it. The folks I'm speaking of, their material circumstances are pretty peripheral to their mentality. Their view of money (whether they have lots or little) is that it's a tool to be used for other ends, and a hazard insofar as it becomes an idol and a distraction. Most tend to be skilled at managing money, I suppose since they govern it and it doesn't govern them.