http://www.komplett.ie/k/ki.aspx?sku=348415 Stick that in any fairly average pc from the last year or two and you'll have graphics as good as the xbox 360; plus a PC that you know, can actually do other things.
The actual cost of a 360 is much higher too; its just that microsoft subsidise it so they can make their money from game sales. The parts inside microsoft's offerings tend to be slightly modified PC parts, to the extent that
anyone with a decent knowledge of computers can install linux on them. The only console that sells at a profit is the Wii, hence Nintendo being sort for the next 20 years or so.