Apparently more relative wealth makes you happier up to a point and then it sort of plateaus. I don't see any evidence that it ever actually hurts to have more money.
I think that's bullshit, it depends upon the attitude to money and more money in my opinion.
In studies of the ratio of wealth to happiness they discovered that there isnt a correlation between more money and more happiness unless at the outset there were predetermining opinions about wealth which became a sort of frame of reference. So if you thought more money meant more happiness and did not make more money you became unhappy. If you didnt have any opinion about money and happiness you were likely to be happy whether you had more or less. If you believed that less money would mean you were happier it didnt matter wether you had more or less either your happiness wasnt contingent on it.
A pretty good lesson against avarice and greed.
Anyway, in response to the question in general, you can never been too thin, too rich or too well armed. Or so they say.