Considering joining marathon maniacs

So I'm really considering joining this crazy group o people, I just think it would be neat to join this elite group of athletes. They don't discriminate against times, as long as you finish. I'd have the chance to do it this coming October. I'm running the Bank of America Chicago Marathon and the day before, close to where I live is the Prairie State marathon in Libertyville. It's so tempting. I have a feeling it would be the best time for me to do it since they're both not too far from home. Any thoughts?