I take your point, and was going to mention varying T&Cs in my post but opted for brevity :shock: .
But if Flex has the most generous T&Cs for the customer, then its the top-of-the-line fare in the cabin class. Any 'sale' under the 'reasonable person' test should be less costly than the most expensive regular option; unless that's true, its not a 'sale' but a 'mark-up'. This case might be more expensive than the cheapo-give-it-away fare (or sofa), but it should be less than what you would ordinarily pay for even one of the choices, shouldn't it?
(And I agree with you wrt 'fair value' - but in this case we are talking about holding out re a type of price - that's a consumer right issue, not a comment on their nous.)
Or am I reading Ansett's table incorrectly?