Apple doesn't set the sales price of the app, though. They only set how much percentage of the sale they take as "rent". Which every store is going to do. You can, right now, build the same app for iOS and Android, and sell it on App Store and Google Play. They're going to take the same cut, more or less. Having another store just means another place that's going to take the same cut. Servers cost what servers cost, bandwidth costs what bandwidth costs, personnel to maintain the servers and customer support etc. costs what it costs. Literally the only way you drop the cost of a product is if you have a competing product. Stores are not competing products. Having 5 apps that track your fuel usage in a store is competing products. *That* drives cost down, not more stores. Sara Lee doesn't drop the cost of a loaf of bread because they can sell it at Walmart, Kmart, Sam's, and Costco. They drop it because Wonder Bread competes with them at those same stores. Wouldn't matter if Walmart was the only store.
In a way, you're substantiating my argument.
Those 5 stores that compete on that markup is what drives the cost down. I do agree that the cost of the app can be fairly immutable. But 30% and even 15% is way way above the actual operational support cost of infrastructure and delivery that Apple purports... competing stores can offer same product "for cheaper" because they don't have a higher cut. But without competition, there's no incentive. Monopolistic practices cause this, and it's anticompetitive because Apple outright forbids any other stores, payment methods, or processing ... even advertising for such .. on their platform.
It's like buying petrol at the Exxon over here because it's cheaper than the Exxon over there.
Alternate app stores often do not charge less though (google play, apple, amazon, galaxy, etc), because there's no incentive to. They're "in on it". It's market cost and no one is going to cut costs just for that reason alone, because it's what the market can bear with limited competition even in the hardware space, they can afford to squeeze it. But I guarantee you the billions of overhead that Apple gets for simply hosting data on sites does not require that level. And their lack of disparate choice is perceived as anti-competitive which is dangerous for everyone.
This goes to my base statement that a lack of competition with the context of the market does nothing to drive the cost down, and quite often does the reverse.
If you lived in the Land of Safeways and you could only get food from Safeway, they could markup the delivery, support, maintenance, care, feeding, nurturing, lights, air, and mental-health therapy of their milk and charge $25 for it, even though the farmer only charges $2.50. All in the name of security (apple line). And we paid SO MUCH to that farmer, says Safeway. Aren't we great, says Safeway. You had a choice through right? You moved to the land of Safeway... so really, you didn't. You'd have to move. Everyone uses that as a line, but the ISV can't compel you to buy a phone. You don't see Spotify saying "we don't support Apple because they're price gougers" but you for sure don't see them taking payments on Apple, and the lawsuits show it. You see ISVs supporting where the users go, but they have no choice in this matter.
*** and to the point of my last post here the market is the Apple App store, which is not the same as the market for hardware: phones have competition. The apple app store does not -- no sideloading, no alternate store, nothing. You're no sooner going to chuck your iphone and buy android as an app developer is going to cut off an arm to deny themselves that market.