The practice of stores like Walmart strongarming producers into reducing prices and quality is a well established problem with a number of articles and documentaries around it already.

In either case the difference between a store doing this and Apple doing this is that Best Buy is not the one of two practical ways to access the product, and consumers are not compelled to go only to Best Buy simply because they chose to go there once.

Figuring out the proper practices for phone app markets is difficult right now, because we really can't compare them to anything that already exists. Physical markets just aren't the same thing.