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)

D&D costs $90 for the hard cover core book set and $0 for the pirated pdfs.

Biking can have a high upfront cost, but I’ve been using the same bike for 20 years with tune-ups and replacements running in the low three figures over that time.

I’m a big fan of podcasts, particularly ones that cover old movies. Criterion collection films are everywhere and they’re classics for a reason.

There are cheaper and better TTRPGs.

Not much is cheaper than free

All the other ones also have copies floating on the great seas, and some are just plain free