How much money to build a desktop?

I am looking to build a computer for a friend and looking about the price of a new pretty nice desktop. He wants it to be able to play newer games such as Diablo 3(when it comes out, etc.). It doesn't have to run it on high def setting or anything but smooth enough to want to play it. I was kind of looking for a ballpark estimation from ground up. Need case, motherboard, processor, power supply, HDD, etc. I am looking for an estimation on price but feel free to provide links to parts that you believe are good parts for their price. **Already stating he isn't trying to go all out, and definitely doesn't need an SSD as I doubt he would be able to take care of one** Thanks to anyone with suggestions.