I think it depends mostly on your learning style. A course can give you the discipline you need, along with help when you need it. If you're able to set a study schedule and stick to it, then that won't be as important. I am doing something in between...self prep with books and an online course (Princeton Review
). I like the course because it's interactive and it's keeping track of my progress, which is keeping me motivated. I didn't sign up for the one with live lectures, but the live instructor chat is very useful. I wasn't sure I would like doing an online course because I'm easily distracted, but so far, that hasn't been a problem.
So that could be one option. They're definitely cheaper than classroom courses (and no driving around!), and you can do it at your own pace.
It really just depends on what works best for you, so I'd say get started more actively with your prep on your own and see where that takes you. You'll figure it out!