So I hear there are still some people who don't have a computer "able to run FFXI" or think they don't. I saw this great deal today and figured I'd let anyone who needed a computer know about it:
http://www.newegg.com/Product/Product.aspx?Item=N82E16883280622
That's your entire computer, though there's a chance you might need a separate video card (since FFXI is so CPU intensive the onboard card might be too slow) so try this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102882
Then you'll need to find a monitor, any old thing will do, though.
Once you take on the rebate the computer + card will cost you $100 + monitor cost. And should run FFXI absolutely fine.