Look at the date of Mavericks on your App Store purchased list, also in your screen shot, the date says Oct. 4.....
This is also what I am getting, I would suspect that you cannot get the download until you see a later date.
My hope is that this was not really supposed to happen yet, and Apple will release an update along with the official release. (I REALLY don't want to do another clean install...)
The original GM was released Oct. 3rd.