Allegro is full of refurb mini PCs, mostly Dells. It is complete computer for less than $100 [0], like https://news.ycombinator.com/item?id=40697831 says, it is very hard to beat it in terms of value. That said it is much harder to get nice notebook/tablet, the wear and tear is very visible on screens/keyboards.

[0] to my surprise the one I grabbed had an internal mono speaker(not beeper) somewhere in the case.