How are the domestic flights organised? Do you need to pass security and passport control? If so then the flight will take considerably more time then the remaining options. And that is not even including the time needed to get from city center to WMSA. The time saving is negligable, the additional comfort doubtful (since you will fly a small plane) and a short flight like this will always be more expensive then the train, let alone the bus. I’d say a flight like this will be booked for the novelty factor ony, and that novelty factor will only work for a short time.