“A life spent making mistakes is not only more honourable, but more useful than a life spent doing nothing.” -George Bernard Shaw
First of all, when assembling your own computer, parts that are used may not always be compatible and it could be a nightmare if you do have an incompatibility of components. Furthermore, you may not receive the latest drivers for the devices, or the latest patches for the operating system
In cases such as incompatibility or outdated drives, constructing your own cpu may tend to have extra carriage costs, meaning that different parts are to be purchased from several different sources, which would probably be more expensive than buying a fully built system.
With regards to performance, your computer may not perform to it’s full potential if it hasn’t been built and configured correctly. You may not be aware of the mandatory versions of the video drivers that provide the best performances.
You are basically your own problem solver. Situations such as the computer failing to boot up would lay consequences depending on how you react. If you can’t solve a problem you come up with you may find that it costs you a lot more time and money than you originally expected.
Poweroid (2007. February). Why not build your own computer? Retrieved January 8, 2009, from http://www.bestpricecomputers.ltd.uk/guides/selfbuild.htm 
