http://www.hotukdeals.com/deals/xbox-one-halo-bundle-299-99-argos-2112026
Halo MCC got a cheap popular bundle which explains the rise.
Kinect AC bundle was available for 349 and normal AC bundle for 299: http://www.hotukdeals.com/deals/xbox-one-500gb-with-assassins-creed-unity-black-flag-bundle-299-99-argos-argos-ebay-2110617
The One and Only