I'm confused. This is very out of context.
I think he was trying to answer a different question ^^
Yeats is a man, so in this case it's his.
In Act 2, Scene 2, Trinculo sees Caliban and perceives him like a monster. People in England would pay good money to see such a freak, says he. Then, when Stephano enters, he also notices Caliban's weird looks, and thinks that he would be a gift worthy of an emperor. Stephano gives him alcohol in order to tame him, reckoning that he would cost even more if he were tame.