And given the pressure to target and go after ever more specialized niches, moderators opt for the free expert that isn't necessarily a good writer over the pro who needs to research a topic for three days AND get paid before cranking out a paragraph. The benefits of the experience in most cases will far outweigh the monetary cost. Freelance writers feel the crunch just like anyone else. In addition, many feel that getting experience or exposure in a certain area provides rewards that are as good as money - especially if they are trying to build their portfolio. Depends on how skillfully you pick your freelancer.
Freelancers are difficult people.
Again, this depends on how well you pick them. Some are also just like you in that they want to be their own boss. Working with a freelancer involves contracts and legal issues that I don't have time to deal with. If something doesn't make sense, ask. Freelancers are usually more concerned about retaining control of their work than trying to bleed you dry for payment for one article.