One way to lessen the cost of a computer is my limiting how much memory comes with it out of the box and how much memory the computer can be upgraded to later. Make sure the computer you have in mind has the following minimums or can be upgraded later before buying it:
Windows XP- at least 1 megabyte (more is better)
Vista - 2 megabytes (4 megabytes is better)
Windows 7 - 2 megabytes (4 megabytes is better)
To determine how much memory your computer can be upgraded to go to:
www.kingston.com and enter the vendor and model number into the memory search screen on the right.