I noticed Artists (illustrators mostly) are getting increasingly desperate to the point that they ended up sending me messages for work even though I’m not a potential client because I’m offering commissions as well. So I don’t know how they see my post and go “Oh, a potential client!” My post says nothing about offering work for them.

Another thing I notice people mentioned supply and demand to justify why prices of commissions are low. 
Supply and demand does not completely influence the entire market. There’s several types of clients in the commission market. Some are price sensitive. Some want a certain style and quality. Some will only commission popular artists. The good unknown artists should target the second group of clients because they are the ones willing to pay for quality and they wouldn’t mind if you’re not a brand name. So please, if you are a really good artist, be kind to yourself and charge appropriately. Go for at least $10-$20 per hour. Weed out those who seek to just use you.

Lastly, about collaborations, I still think collaborations should be between close friends or relatives. Complete strangers asking you to collaborate with them(as in ask you to work for free), don’t take it. “But what if I like the project?” you asked. Then ask yourself this question: Will the person offering this collaboration not flaked out and leave you hanging? Do you really want to work with a complete stranger? Can you use the work as a portfolio piece to show to future clients?
I don’t think I heard any successful free collaborations between two complete strangers. It’s usually collaboration between two friends or two relatives.
I heard some stories that the person who offer the free collaboration will get really overbearing and obnoxious to the point the artist had to stop working with him. I also heard plenty of artists flaked out as well. (But this is expected when it’s not paid) So in the end, the best thing to do is paid the artist. This goes the other ways too. Artists if you want writers/programmers/etc to work on your project, please pay them or do it yourself.