Why do you say $20/hour is a rarity? I still freelance in addition to my fulltime job and the only thing I've done for under $20/hr was for a former co-worker as a favor. It's not an unreasonable amount, given that we're performing a specialized talent, and most developers are willing to pay at least that for quality and reliability. If either of those aren't supplied, I wouldn't expect to be paid at all. Making money and a living hinges on building up a client list and ensuring that these individuals love your work and work ethic. And if that's the case, you're going to see not only your number of opportunities grow, but the monetary amount they'll agree to as well.
I guess I'm saying it's about getting continuous work v. not. And if you can, $20 is probably going to be a number within your reach. Chances are your first jobs (and even maybe your first years) are going to be well under that, but I wouldn't say it's a rare blessing. Freelancers get paid what they ask for. And the freelancer who has enough opportunities presented to him that he can be choosy is going to get the numbers he wants.
Touching on what nvision said, the client is also (or maybe even primarily) paying for your professionalism. Your reliability, constant communication, ease of submissions, correct formatting, intuition, understanding of brand, and so on. It's not just about pixelling ability. It's also about paying someone who gives the client absolutely no headaches, and maybe even (ideally) make the process easier than they imagined. For that, companies will be glad to pay above and beyond because finding all that in an artist who can also draw or pixel well is pretty rare.
"It's RARELY like that. If you're an extremely consistent artist; I would say yes. But if you're just starting out or are a little on the lazy side, I doubt you'll be hitting up that amount of cash any time soon."
If you're not a consistent artist or consider yourself 'lazy', give up the idea of making a living at this now. Freelance pixelling as a primary income is hard as hell. It's not something for the faint of passion.
- Adam