I agree. And I haven't read the book so I'm talking out of my ass.
I just don't see how "women should take advantage of their sexual desirability" follows from "men buy/desire sex more". I mean, if men do
buy "more" sex (very probable), then they're still buying it from someone
, so women are already cashing in on that capital. That's not advice, thats a description of existing unbalanced sexual relations (whatever the cause of that imbalance).