Quantity   Component name
1 × Sharp-edged cutting tool Don't poke your eyes out, though.
1 × 3-Ring Binder Rip out the rings
1 × Computer system unit or small thin client adapted to desktop use, or bare motherboard with CPU and RAM... anything from a smallish MicroATX board on down will do.
1 × Small LCD (7-10" diagonal) and controller, compatible with system unit For a MiniPC or "Compute Stick"/clone, a RasPi 7" HDMI display works nicely. Otherwise, netbook screen with controller board from eBay is probably cheapest.
1 × Compact keyboard, compatible with system unit Should match your local language's standard keyboard layout, or the nearest such layout
1 × Power supply compatible with everything, and rated sufficient to power it all LaCie "Bigger Disk" bricks are good here, as are weird compact-Dell supplies, if you need more than a single voltage
1 × Cable set All the wires you need to connect everything up and have it work.
1 × Some kind of operating system Pre-installed or otherwise. Linux would be preferred over pirated Windows here, for legal as well as other reasons...