Fennelosa starts doing this, with some (but not much) visible irritation.
"Careful with the books," says the boy.
"I'm buying them."
"Looks like you're waving them in the air."
"Well, aren't you a born genius. After I do that, I'll buy them. At a gold apiece."
"They go for four normally."
"You're a bad liar, kid. in-demand books go for two in Cheliax, and Absalom has more trade, so it should be cheaper."
"You're from Cheliax?"
"Yes."
"Well, then, buy them in Cheliax, if you think they're cheaper there."