Icefr, your points 2, 3, and 4 also worry me a bit. I didn't know about point number 5. He thinks he will be able to find employment in Boston, or any other city, after he graduates, but I obviously worry about the chance that doesn't happen! Also, I considered that 26k in a vanguard account to be money I could use toward a down payment as well.
I'd definitely prefer renting alone and building more assets during the two years, but with the rental prices for one bedrooms, I worry there won't be much saving happening!
Tongzhi, he won't have an income during grad school. He might tutor on the side for some extra income, but we're not banking on it. I think I'd be able to find work in Boston fast I'd I had to and wasn't picky. Our families could help us if we really needed it, but I know we'd both hate to ask.