He wouldn't be making that much from actual record sales either. Musicians who are not A+ level currently, for the most part, don't make any money unless they go out on tour and tour consistently.
I went to a concert for a certain very influential heavy metal band from Sweden and got backstage meet-and-greet package and got to talking with these dudes, after they get done with their tour they go back home and get crap jobs because they can't live on their record sales. Now these guys aren't the biggest act in the world by far, but they've been around 25 years and have a lot of clout artistically speaking. You wouldn't think they would have to go home and work in a grocery store to make ends meet.