I seem to recall reading that Gary Holt or Jack Gibson, either from Exodus, claim that despite being known worldwide as a thrash metal act they have to support themselves selling t-shirts, since their earnings from touring, albums or streamings won't cover their expenses
It was likely all of them, but the more famous quote recently from Gary is, “People think, ‘Oh, you're a rich rock star.’ No. I sell shirts outta my fucking closet.”