A first pass at the grad school budget

I'm not sure whether I'm just impatient or have too much time on my hands now that I'm done studying for admissions tests, applying for fellowships, applying to graduate schools, agonizing over whether I'd get in anywhere, visiting schools, and evaluating my options and therefore need something new to obsess over, but I'm pretty eager to see how far my stipend will go. I've done some very rough estimates of what I'll have to work with. I'm trying to err on the side of rounding up expenses to build in some buffer.

Starting stipend: $30,000

Federal taxes: a quick look at this year's form 1040EZ suggests that I'll owe around $2683 each year unless there are major changes in the tax code. I'll guess $3,000 to be safe. FICA isn't an issue for fellowships.
State taxes: A cursory look at this year's state income tax forms from the state in which I'll be living suggests that state income tax will be slightly less than $650.
Stipend after estimated taxes: $26350

Health Care: The university website reveals that graduate student health insurance premiums are about $300 a semester, so $900 annually. The mandatory health center fee is another $900 a year. I'm fairly healthy and not currently on any prescription medications, but I'll budget an extra $200 for incidental medical expenses that aren't covered by the university health center. A health crisis would probably mean spending far more than this and possibly dipping into my HSA, but this would more than cover the average of the past couple of years . (There's a chance that I'll just stay on my parents' insurance during my first year, but I haven't had time to check out what coverage would be like in a new area of the country yet.)
Stipend after estimated taxes and health care:$24,350

Educational expenses: This one is hard to estimate. Tuition should be fully covered, but I will be responsible for some portion of the fees, plus some textbooks and miscellany. I guess I'll estimate $3,000 for now and hope that's high.
Stipend money left for living: $21,350

Housing costs: Craigslist reveals numerous decent looking one bedroom apartments near campus in the $450-$550 range, some including various utilities, which fits well with what current students have told me. I guess I'll estimate $600 per month for now.
Stipend money left for non-rent expenses: $18,950 or around $1,500 a month

Now things start to get squidgy. Some things are easy to guess, others not so much. A bit of googling reveals that an annual bus pass is $60. I know what Netflix and phone service cost, but I don't think I can even come up with a ballpark for utilities yet. Groceries are hard to estimate without visiting a store there. I'm very likely spending a chunk of savings to get a new, or at least newer, car soon so insurance costs will go up, but by how much? Airfare to see my fiancé for a weekend in September would cost $451 if I bought tickets today, but what will prices look like next year, and how often will we be flying back and forth? What does a movie ticket cost? How often would I want to take the train to Chicago for a Saturday away? The mind boggles.

Still, it is looking like I should, with any luck and a bit of planning, be able to keep socking money away for the next three years. After that, I may be relatively broke on RA funding, or if The Boy is done with school and finds a teaching job as planned, we may be able to buckle down and get serious about saving for a house as well as retirement. Here's hoping!