One of the best quotes I have read John in regards to money and happiness is the guy who says I have been rich and I have been broke, and rich is better LOL.
Money is just a means of exchange. Nothing more. Learning and accepting this idea helped me bring more money into my life because instead of it being such a darn emotionally charged subject in my life, I saw it as no big deal. Doing that allowed more money to flow to me.
Sure I was happy first, before having some dough, but since I live a worldly life where we use money to acquire food and dwellings and stuff, it can expand your happiness when you have food in the fridge, a roof over your head, and some neat things to enjoy too.
I also like using money to buy plane tickets so I can circle the globe. I find joy in traveling. I have fun traveling. So being able to purchase plane tickets is certainly happiness inducing.
Money can help you feel free, when you acquire it in harmony with following your passion and rendering helpful service.
As for folks who genuinely believe money cannot buy happiness, most struggle to make money and simply cling to that statement as an excuse to avoid the intelligent, helpful work that if they would dive in to, would help them make more money.