Wheeler put out a blog post:
https://dwheeler.com/blog/2012/02/14/
linking to this blog post:
https://blog.james.rcpt.to/2012/02/13/debian-wheezy-us19-bil...
Saying it's an update of this article. In case you don't like reading URLs, the newer blog post says Debian "wheezy" is worth $19 billion.
I consider this a simplistic analysis, because a closed-source Linux with a straightforward monetary pricetag would be worth a lot less in practice, since it would cease to be the de-facto OS for pretty much all new hardware products. Like BSD before it, which got ported to most workstations because it was freely available, Linux derives a good deal of its value from the fact you can port it to anything that doesn't run away quickly enough without having to pay money or even negotiate to license it from anyone.
Also, this pinged a few neurons deep in my memory, so I found what it made me remember. Back in 2004, some random named Jeff V. Merkey tried to buy a special license to the then-current kernel for $50,000.00:
https://dwheeler.com/essays/linux-kernel-cost.html
In response, Molnar did some quick sloccount math and estimated the kernel as being worth $175,974,824 at that time.
Author here! I was surprised to see this on hacker news, it's a blast from the past.
Ask me anything!