I may be a bit late to respond. I took the exam in 2007. After finishing my courses, I decided to take the exam, so when I failed, I would know what areas I needed to concentrate on during the exam prep course. I passed the exam the 1st time, having never taken the exam prep course.
I guess it depends on how well you did during the courses and how comfortable you are taking tests. It may cost you additional money to take the exam first and know what to concentrate on during the exam prep course, but it's worth a try. Good Luck!