I buy dirt cheap motorcycles(some work but mostly they don't) and customize them then sell them to friends or family. Currently working on a trashed honda rebel 500, thinking on turning that into a dirt bike/chopper hybrid.
I have been playing guitar for about 8 years now. I dont do it very often but I do it on ocasion and when I do it's always fun. I play finger picking songs.
I have generally niche hobbies like cardistry, Pen spinning etc. its just a good way to pass the time and can be relatively inexpensive for a lot of entertainment.