Re: While a 27% hosting fee may seem excessive
"By centralizing ALL software the Apple and Google app stores have solved that problem for developers."
...and have also created another, that is, there are now tens or hundreds of thousands of apps on each app store. There are dozens of apps for even the most trivial functionality. For more common uses there are hundreds of apps. There is really no way a user can properly search through all of that, and the search functionality in-store is (possibly intentionally) crap. Many times I have searched for an app using a specific name, and the app either doesn't show at all, or is way down the list, with a bunch of competitor apps (or completely irrelevant apps) higher up in the list. The searching and ranking algorithms are, of course, highly secret but it would not be surprising if they are prioritised by whichever one gives more revenue to the store.
The 'Best Buy model you describe is quite different. Any computer store could offer a variety of software and games, and developers could sell their software at any one of those stores, as well as online or mail-order with complete freedom. The 50% retail cut is a 'normal' retail cut for a physical store that needs to pay rent and hire staff in a very high staff:sales ratio, and stores could compete against each other by taking a lower cut.
Apple's 30% isn't in itself monopolistic, what's monopolistic is the ban on competing App Stores. The 'payment provider' part is only a small part of it. Apple's insistence that all Apps have to be installed from their App Store is like if a car manufacturer disallowed servicing by any independent garage *that was competent to do so*. I completely agree that having strict App Store rules protect the Apple ecosystem, but in a true competitive market, anyone could run an iPhone-compatible App Store *as long as they could demonstrate equivalent security to Apple's*