Sorry, Lead, but affordable safety is only another term for a cost/benefit analysis.
No need to apologise. I already knew that.
Sometimes you need to quote a ridiculous example to see what that means. For instance, close Ballina aerodrome, make everyone fly to the Gold Coast, then the problem goes away. Clearly that is silly because we can make Ballina much safer without closing it down - oh and incidentally not forcing holidaymakers to drive for an hour on the Pacific Highway - arguably a less safe practise than flying!
But hang on: What has CASA assessed as the probabilities of a mid-air collision involving an RPT aircraft at e.g. Ballina, and what price does CASA attribute to each of the lives involved?
Absent those numbers, the assessment is meaningless.