WALTER IS...unemployed, and makes money through occasional odd jobs and selling things he picks up off the ocean floor as neat little trinkets.

He only spends his money on luxuries now and then because he takes full advantage of the eating situation and other perks of being a gem to avoid needing to spend money on what would usually be necessities. HE...ALSO SOMETIMES nags locals about all the monster-killing he does until he finds someone who thinks that's worth giving him free stuff.

Because he does do a lot of chasing down corrupted gems.

get a real job