If you need a hobby that is really inexpensive try paper modelling.

You can start with free downloads - just Type "paper model" download in Google and you'll get loads of free models which you can print out on cardstock. For some reason big pack of cardstock costs about as much as a twenty sheet pack, so shop around.

There's all sorts of stuff out there, boats, architecture, spacecraft, animals. Whatever your interest.

Then you can progress onto models that you can buy.