Bealzebub said I would be in breach of contract if I failed to turn up for the first sector. Then he said it was up to me whether I turned up. They cannot both be true. That is a fundamental misunderstanding of what a contract is.
Not really - it is up to you if you wish to breach the contract.
I was referring to bealzebub not you. But what do you think? Do you forgo your rights to the main course of a three course lunch, paid for in advance, because you didn't want the starter?
If you had agreed to a contract where for the provision of a fee you would be given a three course meal, provided that you ate all three courses? Yes.
And what has the price of a deal got to do with your obligations/rights under general contract law? Two people sitting next to each other on a flight with exactly the same fare rules can pay totally different prices. That's how the airline likes it, that's what the airline does, don't start arguing you have more rights because you paid more. The airlines will never go for that, and neither would a judge.
You're right. The price has nothing to do with it - the terms and conditions are all that matter. Yet, in general, if you're willing to pay more the airline will offer you more flexible terms.