As far as I know, Becker does not sell the study materials separately. They will want you to buy whole Self Study set of AUD. And, may be you know about it you need to have installed 2011 edition Becker starter software in your computer to run all the Becker materials if you are preparing with 2011 materials which you will get if you buy the study materials directly from Becker. For more details, you can check their website.
I am sorry to hear that you couldn't make it this time. Keep up your study, you will make it next time. I am still waiting for my AUD score.
I used Becker for AUD preparation and I think it prepares you well. I did all the lecture, MCQ, quiz and TBS. Since you said you already used Roger, using Becker will definitely add value to your AUD preparation.