I have spent some time now working with this project and I am really very impressed.  This is the first open-source project I've used that is this complex.  The code base is really very complete.  There is nothing stopping me from customizing the app in any way that I want.  And there are literally thousands of hours in this project.  If this was a project for a medium sized corporation I would SWAG it at $350k plus for the initial release, and then you have at least one major update. 

Don't get me wrong it has some rough edges, but so far I have not had a functionality failure.  My only beef is with the way it displays and does some things.  But all of those I can tweak how I want, and honestly other people might not want those changes.  Documentation is kinda weak, but not bad and better than many projects I have been on.  The rather funny part is I have not went back to the docs one time so far, the comments in the code have been all I needed.   How many projects can you say that about?

Its a one or two minute download and free.  Amazing.