A: I can't spend anymore money after I buy my English textbook.
B: How much is your English textbook?
A: It's $198. I'm not kidding.
B: That's ridiculously expensive! What's the title of the textbook?
A: It's called How to Write Well.
B: Dude, someone is selling that book for $30.
A: No way. What edition is it?
B: I think it was the 10th edition.
A: Oh, no wonder he or she is selling it for only $30.
B: What edition do you need?
A: I need the 21st edition.
B: The publisher seems to be really making money, considering the number of editions.