<p>If I'm taking something like Biology, apart from test format, etc. would it be worth it in your opinion to purchase BOTH the SAT Biology Subject Test prep book and the Biology AP prep book? </p>
<p>If they're essentially similar in what they teach (i.e. covering the same topics), then I rather not purchase both.</p>
<p>I'm talking about both from the same company btw, like PR or Kaplan. </p>
<p>Thanks in advance!</p>