Just bought two of these at Pennant Hills Post Shop, had them scanned and they turned up $9.95 each instead of $39.95. These are not the Chargers that use AA batteries like previous posts, and so far they work very well on my S3!
Also has 3 year warranty and have free connector tips for life.
More info here: http://www.energizerpowerpacks.com/us/products/xp1000/
Edit: looks like it's nationwide and it's on clearance!