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.
Money can't buy happiness but nether could the absence of money. It's not really a good argument against money.