$0.00
I re-read Chris Anderson's Wired article, Free!, this morning – just over a year after reading it when it first came out. A lot has happened in that year. The article grew into a book (which – deftly side-stepping irony – is available to read for free at a small inconvenience), which got slammed by Slate's The Big Money, reflected on by Malcolm Gladwell in The New Yorker, and accused of plagiarism by The Virginia Quarterly Review. (I guess anything's free if you steal it...)
Even after all that, the article still raises some interesting questions. And while artist Laura Gilbert may believe in the Zero Dollar, I'm still convinced there's no such thing as a free lunch.