The Ubuntu software repository contains over 121 million lines of code and is worth over 7 billion dollars

[Kristian Erik Hermansen]

Using the COCOMO model, they estimated the actual cost to produce the
software in the Ubuntu repositories.  Very interesting.  I wonder if
it is accurate, but I wouldn't be surprised if the final number was
close...
http://www.fsckin.com/2007/09/29/giving-away-software-for-free-costs-more-than-you-would-think/

-- 
Kristian Erik Hermansen