I agree, unless he loses more than half his business, why not double his prices? Maybe he only makes one suit a month that way, but he would sure have a lot more free time...
Some people just really love what they do, love being busy, and want to be able to share their gift with more people.
The certainty of constant sales/deal-flow has a value all its own too.
But don't let that stop you parroting the same advice to every self-employed/contractor/business-person who claims to be popular/keeping busy that we see on every. single. thread. on. HN.