For big zones it is relatively cheap (i.e, the cost per domain is low).
Since the invention of anycast routing, it is technically no longer complex.
If a continent fails, then either all BGP announcements are already gone, or you need a way to stop them. Then traffic will be routed to other continents.
It is not trivial, but for big zones if you get 1 euro per domain per year, you can do a lot of stuff.
And that is the sort of prices people cared about back then.
On the other hand, providing support, nobody has any idea how to spec that. What is a reasonable cost? The same goes for payment options.
Since the invention of anycast routing, it is technically no longer complex.
If a continent fails, then either all BGP announcements are already gone, or you need a way to stop them. Then traffic will be routed to other continents.
It is not trivial, but for big zones if you get 1 euro per domain per year, you can do a lot of stuff.
And that is the sort of prices people cared about back then.
On the other hand, providing support, nobody has any idea how to spec that. What is a reasonable cost? The same goes for payment options.