去越南..(關於機票)

No... There is no cheap ticket at the airport being sold...
If you buy a ticket at the airport, it will be a expensive full fare ticket no matter the aircraft is full or not...
This is because they are targetting on business traveller who need to fly urgently for a meeting or something...
And it would 100% be cheaper to book at a travel agency since during low season, the airlines may still have promotional tickets just days before departure... But if you need to book a flight on the day of departure or the day before... It would be really expensive...

係機場只買到全價的機票。
個價錢係個航程,飛幾內你就大概俾幾多錢~