A quick check on Google comes up with the link below:
Google Search for "Desktop computer and monitor for less than $500"
Of course, looking locally in most any sales site gets you a lot of possibilities... Craigslist comes to mind here.
Hope this helps and let us know more.
Grif
have a friend that needs a p c with monitor and keyboard/mouse for $500 or less. For now he only needs it as a word processor with internet capabilities because he wants to start writing again. But he wants to be able to upgrade later and for that I have been told that the ATX tower was the best. Other than that I know nothing.
Any help would be great appreciated
Larry

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