As it turns out it doesn’t actually cost that much on regular transit, there’s an AIRPORT SURCHARGE because it’s an “airport train”.
No wonder Americans don’t use public transit, even when the system exists it’s ridiculously difficult and expensive to use.
I’ve been wondering why this hasn’t become a thing yet. Probably lobbying from all the Verkehrsverbünde.
No, they really want to keep it as cheap as possible. It’s the Bundesregierung that rather subsidises Diesel privileges and Pendlerpauschalen.