Depending on what you need you could buy a Chromebook for $200-250. I was considering getting one, and then installing linux on an SD card (assuming this works on the Samsung Chromebook, have only vaguely looked into it).
If you are into games and are looking to run Steam, I suppose you want more horsepower. I usually buy stuff off of Newegg and build my own if it's not a laptop.
True, I hadn't considered a Chromebook. It could probably do everything I need with EC2 or Linode, but I'm afraid that might up the learning curve a little too much since I'd be completely new to all of those environments.
If you are into games and are looking to run Steam, I suppose you want more horsepower. I usually buy stuff off of Newegg and build my own if it's not a laptop.