$40 firm.

http://www.newegg.com/Product/Product.asp?Item=N82E16811190057

I bought it with the intention of building a mini-pc, but decided to go full size instead. I can still return it to newegg, but I don't feel like dealing with the shipping, so I'll sell it for $40 to a local. It comes with a 270W power supply as well. It is unopened and brand new.

http://images10.newegg.com/NeweggImage/productimage/11-190-057-15.JPG

it also got some great reviews...
http://www.ugo.com/channels/tech/article.asp?articleID=9959
http://www.tweaknews.net/reviews/a100/