What is the cheapest way to get from Phoenix, Arizona to Boston? -

I am a college student on a very tight budget. I figured that if I leave Phoenix on the 26th on Greyhound, it will cost me about $330 round trip with a student discount card, which I will have to buy for $20 so that s $350 total. Amtrak will cost about $700 (from the station in Maricopa, Arizona) round trip.I am really short on cash and will have to stay at a hotel or something in Boston (around Harvard ideally), so I want to find the cheapest way to get there; if anyone has any good ideas for cheap lodging that d be welcome too.So, besides hitchhiking, what would be the cheapest way?

Walking is always the cheapest way The next cheapest will be taking a Greyhound Bus