For a cheapskate - this is probably nuts, but sometimes an experience is worth the price. Marathons are pretty cool. I've only got 2 of them under my belt and I think each of my past ones only cost about $60 each. There's just an element of running a "big one" that is alluring.
What if I don't get accepted? Well there's always next year. I'll pay $11 again. If I don't get accepted in 2013, I'll have guaranteed entry in the 2014 race (because I entered in 2011, 2012, 2013 but didn't get accepted). This policy will be eliminated after 2014 because the rise in popularity of marathon running. So at least I know I'm good for doing it by 2014.
I ran my first marathon in 2001. I can say I ran a marathon before running marathons was cool. I am a trendsetter.