there has to be a list of hobbies one can try that cost practically nothing:

Solving Rubik cubes (a high quality speedcube is about 20$)

Crocheting/stitching (needles and yarn after cheap)

Writing (free)

programming

… (please expand if you have any ideas)

Crocheting/knitting is cheap to try out but once you really get into it (and start worrying about yarn quality and so on), the money pit opens.

ok but that’s in you for getting expensive yarn.

Nah, honestly anything better than the bottom-of-the-barrel acrylics is going to add up quickly when you buy enough of it to make something like a sweater. If you want to use natural fibers (wool, cotton, I’ll take bamboo too) that’s a large jump in price, even if you’re not getting anything too fancy. And I feel like if I’m going to spend months hand-knitting a sweater, I don’t want to end up with something that’s all plastic and will degrade in a year.

I do also have some fancy hand-dyed yarns that were properly expensive and these ones are indeed 100% on me :P But they’re not really what I’m talking about here.