Somebody offered me a couple 386 boards for nothing just last night. I told her to give 'em to my SO who should really have her own computer. You already have the keyboard and monitor. It ain't rocket science, believe me. The difference between using a computer and assembling one is like the difference between playing with handcuffs and playing with rope.
Handcuffs cost forty bucks and work the first time.
Rope costs six bucks and takes some practice. Then go for it. Potentially, this may be true for everyone, but speaking for myself, at present, I'm lucky if I can get a plug in a socket without burning the house down. And the sheer idea of actually putting one of these mysterious machines together by hand blows a major mental fuse. But nessie's an inspiration.