If you want to be happy figure out what you don’t need.
There’s a level at which things can add to our happiness, but more things do not necessarily mean more happiness. You’d probably be happier living in a small house than you would in a cardboard box. But you wouldn’t necessarily be happier in a mansion than you would in a small house.
It also depends on what you’re willing to give up to get that mansion: time, health, relationships, integrity. It matters.
There’s also something to be said for living modestly as a way of not becoming detached from reality.
The question is: how much do you really need? What is the minimum amount? If you’re trying to exceed that minimum what is it that you’re trying to compensate for? What’s missing within you?