This is one of the most absurd tropes in capitalist societies where you literally need money just to exist. No only that, but money literally buys happiness because you can pay other people money to do things you don't want to do, and that frees your time to spend on things you enjoy doing.
Clearly having too much money doesn't buy happiness, but having enough money to live comfortably does. It's also important to account for inflation and other cost of living increases when considering household income.
I don't think that has been demonstrated. Are the super-rich, on balance, the same happiness compared to the merely middle-class?
Yes, I probably should have stated that these were non-adjusted values. This particular 20/20 story was probably in the mid-90s or so, so $30K bought more than it does now.
Yeah, I doubt that having more money makes people less happy. At worst it just stops playing a significant role in happiness.