I'm preparing a talk on the costs of free software for a local IT professional's association (the text will be on my french-speaking blog as the talk will be in that language), and one thing that came to mind is that Open Source has hidden benefits - things that don't necessarily come to mind in a cold financial-only evaluation, but appear when you actually start using Open Source software and making it a strategic part of your infrastructure.

The first hidden benefit is working in a more open way (as thaugt by Open Source communities) inside the company. Sharing more information, being more open to criticism, learning how to criticize in a constructive way, all these skills bring a lot of value inside the company. Open Source projects might be the best "school of life" for IT professionals.

Second, Open Source software has to be based on open protocols to survive - it's not enough to claim that your stuff is based on open protocols, it has to be real or you die. This also brings very important benefits, by creating a more modular, organic and evolving software environment, where forklift upgrades can become unnecessary or at least very rare, which obviously translates to big savings.

Third, being based on standards means that knowledge is portable. I learned Unix and 1986 and still use most of what I learned then in my current activities. Okay, maybe not the termcap stuff, but you get the idea: portable knowledge gives much more value to the learning process, which is a big part of our costs in this industry.

My conclusion will be that it's hard to compare costs precisely between closed and open software, especially for someone currently working with closed software and having to do a big transition. But the above benefits will make a big difference in the medium and long term.

Open Source might not be cheaper today, especially if it involves a transition, but it will make a big difference to your bottom line in the future.