Upon realizing this, I started to try and figure out a way to stay for a few extra days to take in the race. It turns out that I can't, but I will be around Sunday if there are any blog meet-ups planned (and if you'll have me, of course).
I knew that Boston got expensive around the marathon, but until I had to pull out my AMEX card, I never really thought about it. In the end, I decided to go with the Charles Hotel in Harvard Square and some fairly odd flight times on Virgin America, all for $1300. I was hoping for a grand and better flights.
I hope anyone traveling to Boston for the marathon ended up doing OK with hotels and such...