Being retired, I have both time and income. But I also have a slew of hobbies.
In this arena CRPGs and computer games come first.
I have a weekly TTRPG, but my purchases are few. My game is run solely out of the PHB, so I need no splatbooks. I simply convert a lot of the material I have gathered in the decades I've been gaming. I have a laptop I only use for the TTRPG, and I bought three sets of dice this year, but otherwise, I don't buy much.
Since we use a VTT, I download maps off the Net (or buy Oones), and read reviews of published adventures, which usually give the gist of the adventure, and the gist is all I need to create my own version.
Overall. its a very cheap hobby.