Cheap isn't a budget. Might want to let people know how much you have to spend. If its really little/small you have no choice but to buy whatever you can.
Don't write off used either. Nearly a year ago I picked up my laptop off of ebay. C2D, 4GBs of ram, 250GB hdd and a 2600m so I can even do light gaming. Spend less then $200 shipped to my door. If you stick to the shops on ebay you should do alright.