If I was out of school for a year, I'd consider taking a prep course. The idea of failing a test like that and then re-taking is so unpalatable to me that I'd rather over prepare.
Not useful for the OP, but for anyone soon to be graduates - take the exam while you're still in school. End of Junior year is a good time. I, too, did not study (well, I did a little, but it turned out to not be relevant material) for the exam and passed.