Total: ~416$ before taxes/shipping. If you must cut something, you can either change the brand of the 6670 to save 5$, decrease the HD size(or buy a refurb at a gamble). Change the PCI wireless card into a usb one.
p.s: didnt include mouse and keyboard if you needed one.
edit: if your gaming with 1920x1080, good luck with 400$. if its watching movies and stuff, i think it can pass.