The only thing I can think of in this matter is to buy the book from the AU bookstore, look inside the front cover to see what the actual book is ("Taken from... ") and then send it back for a refund and order the other book from somewhere else. This would only work if the book isn't shrink wrapped, and if the custom AU book is the same (no updates or additions) as the book it takes from. As long as you don't mangle the book the bookstore should give a refund.
I noticed when I got my first psy202 book and paid over $100 from it that it was just a different book (could be had cheaper) with a new title and Ashford U printed on the front, so I don't know if all Ashford courses carry similar rip-offs for books.