"At least ninety percent, that's the bottom line."
Noah also understood that when asking someone to do something, you have to offer some compensation. Expecting them to cover costs without paying and still expecting them to work for you is impossible.
Unless you put a sword to their throat, at worst they would be negligently idle, and if they don't cause trouble, that's already good enough.
"Too little!"
"Not little at all, just like that, this is my lowest bottom line, also the maximum I can tolerate. If I find out even one copper coin is missing, I'll dismantle your palace to make up for it."
Noah ignored his nephew's protest, and by the end, he was threatening without any reservations.
This is how much the Giant Dragon values its treasures, and Noah is no exception. Although he spends money extravagantly, it's because he knows that these funds will ultimately flow back to him; spending is just a means to achieve a goal.