Money can buy happiness but not health,
Money can only buy a dopamine rush, not happiness.
It's not the only thing money can buy man, even you could use money to buy the humanity inside some guys too. So i think it's possible to buying happiness with money.
I honestly don't think you've ever experienced true happiness if you really believe that money can buy it. When you buy things your brain releases a chemical as a "reward" for your "work", which gives you a brief rush. Happiness is completely unrelated to such things and comes from within without any reason.