It always depends on the circumstances and the person but generally I would say that money can definitely buy happiness.
I think that sentiment is mostly cope by those less wealthy.
Nah, money can buy pleasure, security, confidence, comfort... but happiness is not necessarily a consequence of that. Some rich people live a very unhappy life. I wouldn't trade places with them for their money.
CAN you be happy because you have money? Yeah, why not. WILL you be happy if you have money? No guarantees at all.