<p>I was looking online at the Real ACT Prep Book 3rd edition (2011) and the one with CD ISBN 9780768934403 retails for about $19 while the one without CD ISBN 9780768934328 retails for about $24.
I understand that the CD is useless (just college planning info) but aren’t the books supposed to be identical?
Why is the one with CD cheaper?</p>