As jitpublisher correctly pointed out the item is out of stock. You can't buy it. I checked prices in half a dozen pc categories and dozens of items. The prices looked okay. Probably just an error on their part.
Current low price in the USA is $269.99 at Best Buy:
Ok, I decided to part with $60 and try my luck... I'm all the way to checkout and it looks like its working. Most likely they will realize the mistake and refund us but you never know I guess... at least its not $400... that would be a waste :-(