It's one thing to charge a 30% app tax to sign up for "Jasper's Cooking Class" on an iOS device, but it's even worse to ban disclosure of that tax. Forbidding that speech is certainly 1984-esque.
The problem is, the chick with the hammer wouldn't make it past the cheap seats today.
They CANNOT force you to remove transparency and visibility of the line items. I understand that they want to hide the 30% cut and not being called out.
They can also split the receipt in three parts:
A) you purchased:
Pizza $15, Salad $15, Soft drink $3
B) Other fees:
Apple's 30% fee $10
C) Taxes:
VAT $3
Edit: it just hit me. Don't write that ONLY in the receipt. Write it up front, BEFORE a user completes the transaction. Total price of ticket $10. Analysis.. X, Y 30% Apple's fee, VAT.
If I'd take your analogy it'd be more like the government forbidding walmart to say how much VAT is in the purchase price for a can of coke.