If he's trying to build up a portfolio of work, he'd normally be doing it for free, why would he be trying to make market rates? You're assuming that this is someone building a living from this.
But if he spends more time on the early projects (say, 10 hours each to showcase his best work), eventually he will have to cut down the time per project or increase the price to make it profitable. In that case, he would Need complete rebranding, which would be tough, since people would know him as the cheap design guy. If he were just after the portfolio, he should design 10 designs on spec and put them on a site that pitches high end design from the start.
No, it's not done for free. It's an investment of time designed to earn a return. The value of that time is supposed to be included in the price charged to the client. 'Doing it for free' is about giving value, not the inability to get paid.
