Well, the truth of it is this hand did not cost $1,000 or $2,000. In other words, if you started from not having an initial design and iterated through the many designs leading up to the latest the picture is quite different. Add-up engineering costs at a reasonable rate and the total cost of executing a design --even for a diy case-- is significantly higher.

Once you get to a commercial enterprise things are quite different. Even a small-is company is likely to have 5 to 20 employees, rent, equipment, computers, software and other variable and fixed costs. In addition to that they need to provide sales and post-sales support and stand behind their product for many years. Prototyping and testing alone could easily cost hundreds of thousands of dollars per iteration.

Product Design and Development [0] is a fantastic book that provides insight into the development process for a wide range of products. I have a 1995 edition. It goes from a screwdriver through to engine parts and the mechanical trackball on Apple's old laptops. If you've never been exposed to professional product development and are interested in learning more I'd recommend picking up an older version of this book ($200 for the latest version).

[0] http://www.amazon.com/Product-Design-Development-Karl-Ulrich...