Should "How much for this breakfast be accepted" be accepted? I feel like this is a fine variant and would be used in English.
What you've written sounds wrong. Maybe it's because I'm Australian, but the correct wording to me would be, "How much for this breakfast would be accepted?" or, "How much would you accept for this breakfast?"
That said, both are very uncommon ways of asking in my country... maybe not in the UK :)
I think he meant:
"How much for this breakfast", as well as
"How much is this breakfast" should be accepted.