Your DVDs would look better photographed more square on, I think.
If you did the back as well, it would give people a lot of information they may not bother to ask you for, and not buy.
I'm not suggesting you re-do all the photographs, but get the best you can for future ones. You can crop and improve the colours with a simple photo editor. Fastone Image Viewer is good, and it's free.
Best of luck with sales