Apple's offerings may have been good when the alternative was software sold on physical CD's in a store, but compared to the alternatives today there is no way 30% is by any means fair or reasonable. The 30% commission is essentially monopoly rents.
You don't need both Billing and Invoicing. Invoicing is for one-time payments (typically after a service has been delivered), and Billing is for recurring payments.
All in all, we're looking at $0.30 + 3.4% (or 3.3%). This is clearly lower than 30%, except for very inexpensive apps (~$1.29 or less).
Apple's offerings may have been good when the alternative was software sold on physical CD's in a store, but compared to the alternatives today there is no way 30% is by any means fair or reasonable. The 30% commission is essentially monopoly rents.
1. https://stripe.com/billing