Wow, this is an excellent idea.
I can imagine building and ordering spare parts for defective and unsupported electronic devices that would prolong their life.
I can also imagine experimenting with building and fiddling with guitar pedal effects from the slew of existing schematics on the Web.
I think the hardest thing for me is going out finding and buying the parts. Some times I might have the time to assemble them but most of the time I wouldn't.