This is a really unorthodox suggestion, but you could have your friend check some pawn shops if you think they're knowledgeable enough to not get burned. They'll have to wade through plenty of trash, but I know several people that have ended up with some great deals by going this route. Just make sure to thoroughly inspect, test, and ask about the return policy. I actually picked up an HP ProBook 4730s in like new condition a few years back for $150, and aside from recently having to replace the fan, it's still going strong. They actually had it on the shelf for $300, but shops know electronics lose value quickly, and cash is king. (refurbs of that model were going for about $900 at the time)
Good luck, and happy hunting!