What I've learned, both in terms of personal experience and from reading up on the psychology, is that to maximize happiness over time you need to optimize for ensuring you can maintain a steady upward trajectory.

Win the lottery or sell a company? Invest most of it, and allow yourself a "raise" you can permanently sustain every year.

It will do far more for you than raising your expenditure once, as you get used to it and return to near your baseline happiness very quickly.