Companies should be free to compete on various variables, which include price for their services. But there is no competition for the Apple AppStore on Apple devices, it's a captive market. At that point, it's not competition but exploitation; and exploitation surely is a Bad Thing.

We used to be taught that one of the Bad Elements of feudal life was that the local lord could impose arbitrary taxes to use a road or a bridge, with no recourse for people and tradesmen. Now we are at the same point in the digital world.

There's plenty of good reasons to charge different amounts for the same services. There's nothing immoral about that. People can simply say no to making the purchase for the price offered to them. Again, this is completely besides the point of the Apple case.

In Apple's case there are no reasonable alternatives and no practical way to say "no" to the service if you want any business at all. That and that alone should be the issue at hand. What Apple is doing should not be legal on that ground. Either they allow third party stores, or they adjust their cut to a level that can reasonably argued is aligned with the value they're adding to the publisher of that app or service. Now they're in "we can charge whatever because we're the only route to getting your product on Apple products" land, and that's just not where we want to be.