Hey,
I'ver got the same problem, I want to buy a new laptop because I'm starting uni but I don't really have a lot of money.
I'vebeen looking into and the refurbished and clearance laptops seem to give the best deal. So don't be put off just because the website says they are refurbished, they are fully operational and usually come with a warranty. They start from £250 and seem to match what I'm looking for - enough memory to allow me to store MS Office, downlaod music and surf the net. You should look them up on Currys, PC World or Laptop Direct.
You can get netbook from about £160 but they have quite small screens so they can be difficult to use for lon periods of time. But they are good if your just going to browse the net, check e-mails and maybe use MS Works, but if you want to do more than that like play games, download etc your probably best with a laptop.
My only advice is think about what your going to use your laptop for and then look at laptops that meet your requirements. Shop around and research it thouroghly, if your anything like me buying a laptop will be a big investment (even though I'm only spnding £300 max, its still a lot of money to me :P). Also don'y just look at the big stores or supermarkets, you've probably got some local computing shops in your area which will probably be able to give you some good advice and give you a good deal.
Hope this helped and wish you luck =D xx