Well, I would like to see and expect a difference in buying parts needed for an open source hardware project and buying commercial customs.
The resulting problem of keeping productions files closed is, that there's only one single source. Which is completly contrary to an open advertisement. Daniel has an interesting point with his estimate, that the production cost is actuallly more like 10$ for Arduino boards. I recently stumbled upon this: Ihr Online-Shop für Elektronik, Technik & mehr | Pollin Electronic.
Ok, it doens't come with an Atmega8 (because you can choose between several ATmegas and ATtinys) and there's no FTDI USB serial converter. BUT, please note, the PCB uses more than twice the area of an an Ardunio Board, has many many more parts on it and is still only 15 Euro. And like it's with nearly any board, whicht features an Atmega8 or 168, you could use it as a replacement for an original arduino board - if, but only if, you are experienced. (I'm speaking in general of ATmega boards from manufacturers that probably even don't know about the existance of the ardunio project, e.g. like pollin.. 
)
Why should only people with experience in electronics have the opportunity to try out Arduino at lower costs, with lower priced boards? Esp. when its a known fact, that those experienced poeple are not the majority of ardunio users.
Really, I don't want to offend any developer now, but look at what's the ardunio board when it comes down to the schematic.
It's not more than a combination of the Atmel AVR Atmeg8 reference design together with the FTDI232R Serial-USB chip reference design. Even the serial bootloader idea isn't original.
It's the software (the IDE and the libs) that make ardunio great and usefull!
Why should the constantly growing arduino community still rely on a very commercial distribution of the main component?
Oli