Ok after spending hours with Senior techs (2 very nice ladies) and waiting for Engineering to review my logs this is where I am.
First lady had me delete prefs, reinstall iTunes create new user etc.etc. The new user account seemed to work at least at first. I searched my drive for old security components from deleted software, removed all 3rd party music players, etc, etc.
Second lady informed me that Eng say there is a network problem and I need to create yet another new user and bring things back over by hand and not with TM. But because this is so annoying to me I was willing to try. Having checked the new users ability to successfully pull up the purchased screen I was happy to do the work. About half way in I checked to make sure it was still working and no joy? Ok now I'm thinking it is possibly a software conflict.
The problem with the Eng's assessment is that I can pull up the page on my iPad, iPhone and laptop via the same network. But I decided to push a little farther. The tech also thought there might be a problem with the user account.
So I completely wiped my computer, reinstalled 10.9 and reinstalled only apple software ... pages, keynote, etc. and found that iTunes would not launch at all!!! I reinstalled iTunes and I was able to launch the program but still had a blank page at the purchased button on the iTunes store. I give up. There is clearly something going on that is not something the user can fix. I think Ernie Goldstein is right. There is a bug in Itunes or 10.9 that is only hitting some computers but only Apple can fix it and I do not think they have identified the cause.