Yep, and I happily spend a fair amount of my free time working on open source, as well as personal projects that I don't make any money from. I'm also currently helping a friend of mine learn to code just for fun and to give back. But when I do contract work, I expect to be paid well. If you said, "well, I'll pay you $10 / hour, and that's way better than what you get for this open source you work on!", I'd not only not do the job, I'd be insulted.