<p>Amazon shows that their is a newer 12th edition of that book, which is much more likely to be the one that the Cal custom edition is based upon, given the 2010 date for the Cal edition. Also, the student solution manual they suggest to use with the text is based on this 12th edition.</p>
<p>The current 12th edition text on Amazon is $114, the bookstore custom edition is $46.75 and Ned’s is $46.50. Since it is only about half the book that you use (the back half which is what the V2 custom edition holds (V1 is the first half for math 16a), the custom edition is much smaller as well as less expensive.</p>