Retailers have substantial costs associated with distributing products and physical shelf space is a scarce resource. There are, by comparison, no limits to the number of apps on Apple and Google's "stores" and we know that the costs of maintaining them are quite low because the respective business units are wildly profitable.
The points you raised are the rather beguiling false equivalencies that have been propagated largely by people with a vested interest in preserving this system and averting scrutiny.
Sorry, between this line and not realizing you were also the GP commenter, I assumed you were suggesting the markets be forced to disclose the rake pro-actively themselves.
Making it illegal to prohibit disclosing the fee is great, and at that point I don't even think you need to make the case that the industry is different than others. It's not the same as the cost, but plenty of items have an msrp listed on their packaging. You know if your Arizona Iced Tea is being sold at a higher than usual mark-up because it's not $1.
(Disclosure: I live in San Francisco and have no idea whether Arizona is actually still a dollar in other places.)
Printing MSRP on the product happens all the time. Arizona Iced Tea is a prominent example.
Are you sure that they don't? I honestly wouldn't be surprised if Walmart does have clear policies around prices of any kind being printed on packaging. And it wouldn't be a stretch to assume that if they have a policy, it would disallow printing of any price which is less than the highest price Walmart intend to charge at retail.
Meanwhile, I'm merely saying that it wouldn't surprise me if such a policy exists, whether formally or informally. The distinct lack of any product on Walmart shelves which has a below-RRP price printed on its packaging is strong circumstantial evidence at the very least.
The fact that you mentioned is an extremely weak evidence in the light of very thin margins Walmart has (under 3%), which is more than 10 times less than the old store tax, with probably even smaller incentive to combat.
Oh, and the Apple car has an extra trick up its sleeve: it makes it nearly impossible to shoplift, which allows products to be sold at a dramatically lower price. Potentially far less than if shoplifting were as commonplace as it is among drivers of Windows cars.
Of course the producer of the product always decides how much the customer pays. It's up to them to decide whether to reduce prices in response to the elimination of shoplifting.
The broader point is that just saying "oh, it's like X, therefore we should treat it like X!" just isn't enough for app stores. There is no perfect analogue. Apple and Google call them "stores" because they really want them to be thought of that way, but there are important features of phyiscal stores that the app stores lack, and important features of app stores that physical stores lack.
How we, as a nation and a society, decide to treat app stores for purposes of consumer protection laws is up to us... so let's be careful just blindly trusting the way these companies want us to think about them.