Looks like you are not looking at the eBay completed item history correctly.
Couple of pointers.
1. Sort by highest price first in the completed items.
2. Generally, if 1/5 have sold, it is a good eBook.
3. If not that many have sold, it does not follow it is not a good eBook. It could be simply because the people selling suck at selling. There are so many variables that I am thinking of right now, that could cause non-sale. For instance, assuming all of the sellers copied each other, which they generally do, if they all but one copied each other and the one that did not copy had the superior ad and was selling 1/2 of his auctions, while the others were selling 1/15 of their auctions, one can conclude it is a good eBook, and to follow a pattern similar to the one that sells 1/2 his auctions.
4. The fact is, the sale has little to do with the eBook itself. It has more to do with how you sell it.. About 75% of it is how you market it. If you don't know how to market, you will be like the peons on the bottom selling it for 1 penny and making no money.