The German GiroCard payment system is 0.125%.
The EU just limited credit card inter bank exchange fees to 0.2%.
Re:Apple, Epic, and the App Store
by jagged-chisel on Monday August 17, 2020 @02:35PM
(#24190298)
$0.329 for one dollar.
$0.59 in CC fees for ten dollars. That's 5.9%
$0.735 in CC fees for $15: 4.9%
Part of the problem with this whole market is that we're talking about zero marginal cost goods. Taking away frictional costs of transaction, distribution and support, the economic argument is for prices to trend towards $0. Hence the "race to the bottom" once the App Store made distribution "free" for free apps.
[1]: https://stripe.com/pricing