Even the most expensive PC is useless without a keyboard and mouse. And, things happen (to use the polite version). Spill some coffee on your keyboard or otherwise damage one of these devices, then go running around computer stores and searching through mail order outlets for a spare.

We spend so much time choosing processors, monitors, printers, etc., that we forget about the input devices. More than likely you will not be able to operate your machine without a keyboard or mouse, so why not purchase an extra one as a backup? Keyboards and mice are cheap, and the cost of purchasing backups can be well offset by the time you save by not having to run frantically to computer stores and outlets looking for a replacement when one dies.

Keyboards and mice do not last forever - you should prepare for the inevitable and save yourself some grief.