A good place to pick up a dell computer for a better price is the Dell Outlet. Sometimes there are some really good deals there. Go to http://www.dell.com
and click on "Home and Office" under Solutions on the right hand side. It will bring up a window with drop down menus across the top, one of which is called Dell Outlet.
Dell Outlet has Dell machines that have been scratched or broken and have had a part replaced. I have seen an XPS laptop with 120GB, 1.5GB and a 128 video card going for $480 before shipping and adding anything. I think it was about $550 after shipping and an upgrade I was considering.
While I ended up buying a Mac instead and have never bought from the Outlet, a friend told me good things about it, which is why I checked it out. Other than that, craigslist.com is a good place to find a used laptop for a good price. It's a local free advertising that covers many cities in the world. It gives you an opportunity to see what it is before purchasing since the seller will be local.
Hope this helps,