Those are very cheap but if you’re interested you’ll need to book soon, because there’s always a heavy demand for them.
adv. as soon as sth：一…就…
She burst into tears as soon as she saw him.
adv. would just as soon do sth：宁愿做某事
I'd just as soon go by train as drive.
It's too soon to talk about stopping.
How soon can you come back?
The plane was returning to the airport soon after takeoff when it burst into flames.
Soon afterwards he separated from his wife.
It will be Christmas soon.
I soon forgot about our conversation.
I realized quite soon that she was different from any of the teachers I'd had.
You'll be hearing from us very soon.
I have to tell him as soon as possible.