The value of open source

What is the value of open source? I don't mean what it is worth hypothetically to mankind. No, I mean cash, hard cash. After all, it does pay to use open source, you get quality software and probably a fair bit of community support. The question is, what is it worth to you or your company to be able to use open source?

I see two possible ways of exchanging that value. One is to put value back into open source, by committing on projects in whatever way you can. The other is to carefully pick a good cause and commit to that. It can even help support the story of your company / product. But you have to be careful to give in the same spirit as you have received from the open source community. With great passion and incessantly.