Thinking of buying a laptop

Not quite...but close

I actually just linked both of these in another thread regarding an old airport card but they almost fit the bill here too. Looks like they are a little more than you wanted to spend, but they are also a "better(newer)" model. Plus it saves you from ebay.

I sold stuff to them once, but I have never purchased anything. I have heard good things though.

http://www.macofalltrades.com/

also may want to check www.powermax.com
They usually have a lot of older stuff, though it is usually expensive. I have bought a new machine from them, and was very pleased with the service.

hope this helps.