Utilization Review ??'s

I am interested in pursuing a certification in Utilization Review. I worked in UR for two years, but it has been three years since I have done that. To make myself more marketable I want to take the CPUR. According to McKesson's website they have a study guide for $150 and you have 1 yr to complete. How long will it take me to finish the study course if I actively pursued it? Can I buy a study guide somewhere cheaper and still be recognized by McKesson? Any ideas/thoughts will be greatly appreciated. Thanks.