Define “healthy”, OP. Like, mentally healthy? That’s pretty dependent on what your personal tastes are - the game is to find the things you can tolerate that most people can’t as well, and to save on whatever those may be. Medically healthy? Aside from food most unhealthy habits are expensive anyway. If food, canned veggies are underrated, at least where I live.

One pretty universal thing, I guess, is not spending on the first thing put in front of you, metaphorically or physically. The entire surveillance capitalism and marketing economy is set up to part idiots from their money that way.