You keep wanting to leave off part of the sentence. But, no, that's not what we were discussing.We are discussing pricing. I'm sorry if you don't understand the Third Degree Price Discrimination illustration. But it's OK. I don't understand "cascading costs".
I understand enough about the link you posted to see that it is an off-topic red herring which you keep trying to drag into the thread.
It's not what was being discussed no matter how you try make it smell like a rose - it's still a red herrring.
If it pleases you to keep saying you don't understand cascading costs go right ahead and get it off your chest. That much is clear from your postings.