The first link at Buy.com states "6x". The 2nd link, at CostCentral, states "2.4x". I would pay the extra 84 cents at Buy.com (whom I have done business with) for the 6x media.
But if memory serves, the free shipping at Buy.com only applies to orders over $25, so you will need to find a filler or else buy two of the 3-packs.
At any rate, I am STILL not buying any dual layer disks. Just too d*mn expensive for a tightwad like me.