I think happiness and money aren't correlated in the exception when you are starving, having no clothes or no shelter to sleep in.
The "Love of Money" can be the root of all evil indeed because money is not an end in itself. It's one of the most direct mean to acquire resources but if one's goal is money itself he will sooner realize that "there is no there there".
Since I am now quite significantly more wealthy than I was 3 months ago, I can say that I think a lot less about money than I use to since I'm not always wondering if the I'm gonna receive a call from the bill collectors.
Also, if you are an asshole, money will probably make you an even bigger asshole.
I hadn't thought of it that way :) It's like the perfect comment!