Here's my thought: I'd rather have a second-hand but well-built laptop than a new but built-down-to-a-price one. I have an ageing IBM laptop that's been going for nearly five years and is still fast enough for all general purpose tasks that I do.
So without having used the company before, I'd look closely at this page
http://www.student-laptops.co.uk/aca..._with_DVD.html
especially the IBM T21/22/23 models because I know they're built well.