Umm, I pay for my free software by giving back to free software. I also periodically give back to free software by paying for free software. Not everybody can give back, and not everybody will give back, but that's OK (as per the licences). I also earn money (in large part) because I know free software... Funny that...
Before a person says, "well I can't code so I can't give back!", you can: Translate, do art, do documentation, do bug triage, do web design, donate to projects / distros (or buy commercial versions of software / support), provide support for projects / distros, etc. Do I advocate doing skilled labour for free out of a fanatical sense of devotion? No. But if you have an itch to scratch you should consider putting it under a free or open licence (and seeing where it goes). If there's a bit of free or open software you like, love, or 'use lots', and you can help a bit, then help a bit. Even if you don't get directly paid you: a) learn things, b) build skills (that often can go on resumes), c) meet people, and / or d) can have it lead to a paid job.
My Linux use predates KDE 1.0, and Kernel 2.0. AKA- the scary ass bad old days. My decision to use Linux has proven to be both personally and professionally rewarding. Free has both costed and given a lot but has ultimately been to my benefit, and to the benefit to literally anybody that uses anything with a CPU. Not bad...
