Image Courtesy ASUSTeK
It seems like very low cost laptops are becoming harder to find thanks to the growth of tablets. If you do need a computer that is portable and can do a bit more than a tablet, then the ASUS X55C from Best Buy for just $370 might be a good option. The system uses an older Core i3-2370M dual core processor with 4GB of DDR3 memory but this is sufficient for most peoples. Other features include a 500GB hard drive, dual layer DVD burner, 15.6" display, 802.11b/g/n wireless and Windows 8 operating system. This is very similar to the ASUS X54C I reviewed last October other than the X55C swaps some RAM for a larger hard drive and comes with Windows 8.
Disclaimer: All deals are those advertised by the retailer in question and may have rebates or other conditions of purchase for the products. Please be sure to read all disclaimers from the seller before purchasing.