<p>I found several AP test prep books on Amazon for only 1 cent plus shipping, but realized that they were outdated by 5 years. Could there be a big enough difference in content between the 2007 and 2011 books to warrant spending the extra money?</p>
<p>make sure to download the course descriptions for each class and check to see what topics are covered. then compare the topics being tested on this year to those that are covered in the ap review book. often times the reviews point out some of these differences and changes, so make sure to look over the reviews that are from this year or fairly recent.</p>