Wages are only part (I've heard 50% before) of the cost of hiring. There are other expenses like training, desk space, insurance, etc. So I can't imagine that it'd be much easier getting an unpaid position as a paid one. At the very least there'd have to be some expectation that you'd offer a return on any training you receive. If you've got the potential, they'd probably just pay you. There's nothing stopping them from employing casually or on a short term contract to alleviate risk. Taking people on for free might even violate labour laws in some jurisdictions.
Volunteering for a not-for-profit is a different matter of course.
Volunteering for a not-for-profit is a different matter of course.