Buy a crappy laptop (Score 1)

Just buy a crappy laptop (486). If you get one that has easily replacable parts, like a thinkpad or a toshiba, then you don't have to worry about warranty etc. I'm very happy with the one I bought on ebay (~$150). One word of warning, however: you won't get a good battery. That's just the way it is. If you are looking for portability farther than an extension cord away from a wall socket, then you might need to pay.