Money is just a medium of exchange for the pursuit of pleasure and avoidance of pain. That is, money today as we exist in a Monetarist system, where money is deemed to be "intrinsic" in value, in any form. It just enables usury at the expense of real physical productive economic activity, which is the real wealth produced by man's creative abilities. So I'd say the definition of happiness, used here, is relative to an Imperial system of money and cultural degeneracy.
Love can't be bought, and even if it could be, it'd be overpriced, and without it, no happiness.
Money can definitely buy happiness, but only the temporary kind. It is joy that money cannot buy, that is what lasts.
The difference is that joy manifests itself outside physical circumstances. Joy is able to endure even in bad situations, while happiness is something evoked by good times and situations. Example: Someone that you love very dearly dies. Before their death, they were in immense pain. After they die, you still are extremely sad, and clearly NOT happy about the situation, but you have a deeper joy in knowing that they are not in pain anymore.
Its kind of a different concept, because most people equate joy with happiness, but I think there is a distinct difference.
Edit: A lot of times joy is seen hand-in-hand with happiness, because that is where it is the most common and the most visible, and that is probably what makes it hard to recognize and distinguish.
Joy is a candle flame and happiness is a spark.
Morality isn't a product of money, money is a product of morality. I'm tired of these people getting that confused.
I would rather have temporary joy than permanent misery!