option 1) go to
www.slickdeals.net and search for "laptop" or "notebook"
for example, this looks somewhat promising
http://slickdeals.net/forums/showthr...id=0&t=2284203
option 2) the classified sections of online tech forums are usually good places to get used computers e.g. notebookreview. Although they usually impose a min post count limit to access their classified sections to avoid fraud so you kind of need to already be a member/know someone who is.
option 3) the lenevo budget laptop lines are typically decent and are cheap, especially if you can get them on sale. About a year ago, I got my sister a 15" G530 with a core duo cpu for like $270 (I miss Bing cash back
). Slickdeals.net is a good place to be notified of said sales.