I don't know that you were necessarily thinking of this, but I did write a piece on exactly this in 2004.[0][1] I couldn't really find anything else at the time that was talking about this, so if you did/do find something else, I would love to read it!

[0] http://dtrace.org/blogs/bmc/2004/08/28/the-economics-of-soft...

[1] http://dtrace.org/blogs/bmc/2004/12/16/the-economics-of-soft...