Acer AM3450-UR10P PT.SHDP2.004 Desktop PC for $449.99 shipped.  Here is a screenshot for your reference.  It features the new AMD Bulldozer FX-8100 8-core CPU, 6GB DDR3 RAM, 1TB hard drive, ATI Radeon HD 7350 graphics, USB 3.0, 802.11b/g/n wireless, gigabit ethernet, dual layer DVD burner, Windows 7 Home Premium (64-bit), and more.  This is a pretty inexpensive way to get an 8-core CPU PC.