Interesting. By more expensive on average, would this mean pursuing personal interests, with the price being the opportunity cost of hours of labor that could have been exchanged for salary?

If so, this resonates with me. I would add that there's another component to this equation that I found personally valuable: challenge. The challenges that I have faced in professional roles (some unpleasant) have often forced me to grow. During long periods spent away from work, I often came to miss that.