Steve Wozniak built the Apple I computer by hand, and it sold at US$666.66 when it went on sale July 1976. And with a product called SmartyKit you can build a replica of it.
Besides a cool DIY project, the company behind SmartyKit also proposes it as an educational tool for those interested in knowing what are the main parts of every computer, what a processor is and how it works, how a video signal is formed and how a simple operating system works.
Check It Out: Build an Apple I Replica With This $99 SmartyKit