Wow! Mega-props to both of you. :)
I'm not as hardcore, but also a PhD student (4th year in engineering at a university in a cornfield). I'm too shy to share the particulars (for now), but I'm willing to share my top "assets" and my top goals.
#1: never carried CC debt* (*that I couldn't pay off. I carried a few hundred last winter when my conference reimbursement got delayed and I was only willing to take so much out of savings for that. The $5 in interest was worth the psychological benefit. Antimustachian? Maybe. But it was a one-time, calculated loss.)
#2: Never had a car. I have Zipcar for the very occasional (<1x/mo) driving I do. Used the bus system (free for students) for 3 years, finally gave up fixing a bike and bought one this June, been biking since for the health benefit. :)
#3: "Student loans" are through family, so near 0% interest. On the other hand, they aren't holding me as strictly accountable as a real lender would (it's easy to get lazy when your lender is ok with payments at-will). Not complaining, though, it's a good arrangement.
#1: control ridiculous food spending. It's currently my biggest identified money-sink. Groceries is $300 (I expect this includes some personal care, cleaning, etc products, but it's still high!) and eating out (I'm ashamed to say) is $200. Bet I can go down to $200/$100 easy (i.e. feeling accomplished rather than deprived).
#2: Start air-drying clothes and change my lightbulbs to CFL's. Then show roommate the results and convince her to do the same with remaining bulbs.
#3: Identify other money-sinks. :/
...all of which will allow me to #4: Start paying back those "student loans" again...>_>
#1: How much rice/pasta and beans vs veggies and meat does that $60/mo or $100/mo food budget include? [I have hated beans my whole life but might accept them in unrecognizable form now, e.g. chili; I'm trying to limit starches, so pasta or rice as a staple is out.]
#2: What resources would you recommend for learning how/where to invest as a grad student (besides this site)? e.g. I don't even know who to approach on campus/in payroll about doing IRA contributions...