Incidentally, during the time when Luke purchased a single bottle it was 15 Asura Gold Coins.
He bought five of those and among them used two for times when he was in bad condition.
The effect is guaranteed.
"I thought to use it as a treasure fund if the time ever came to it, but Sylphy, I'll give it to you."
"Luke, this kind of expensive thing...is it fine?"
"Of course.