Was it then impossible for the OSx user to resort the content and find a better price? If so I would agree about the questionable ethics. On the other hand, if the user simply accepts what is displayed without doing further research they are just as culpable...if, indeed, there is any culpability to be assigned.

Many years ago I learned that just because you see SALE in huge letters in a store window (an early physical corollary to a web page :-)) it does NOT mean that the prices you will find are lower. In fact it was proven that the impression of a SALE would bring in customer more than willing to pay more because they forgot the basic rule of commerce: caveat emptor.