There seem to be two different versions of the Munchkin Mozart Magic Cube. My best guess is that the version above is the older style. It seems to be more rare, which means it generally sells for more on eBay.
I found the above cube at a thrift a few weeks ago. And I left it behind!! I was being super picky with what I bought because I knew the store was having a 50% off *everything* sale a couple days later (the first of its kind as far as I know, usually this particular store only does 50% off clothes/bed/bath). So there were several things I had been eyeballing that I was hoping would still be there when the sale rolled around. Luckily, the toy was still there, and this time I looked it up, and quickly put it in my cart!
It sold two days after I listed it, and the buyer actually messaged me hoping I had more of them I could also sell him. (I wish I did!) Even the used ones of this style seem to sell consistently. Happy hunting!