Between federal loans and Grad Plus loans, you will be fine. Federal loans give ~20,000 every 2 semesters and I think Grad Plus gives $19,800. Those numbers are rough estimates, so someone may be able to post exact amounts. Currently, interest rates are higher on Grad plus loans, so you want to delay taking a Grad Plus, or take as little Grad Plus as possible.
Some cost saving tips:
-If you live with someone in the program, you can share books. My roommate and I share books, so I only have to buy about 1/2 of them
-Live on public transportation (if you're in a city that has that). Often times, this is much cheaper than insuring a car, paying for gas, and paying for maintenance on the car
-Plan your meals based on what is on sale every week at the grocery store. So I personally look at the ads before I go to the store, and only buy what is on sale. While it may only save $40 or $50 a month, over a year, that can save me $500+. Also, make a list and stick to it. This will help you not to splurge excessively on things you don't need. Finally, pack your lunch every day to take to school. This will be cheaper than buying lunch.
-Don't live alone. Rent is so much more expensive that way. Also, keep your AC and heat off for as long as possible, if you pay the utility bill. Again, only a few dollar savings here and there, but I like to think that it all adds up
In my program, I think there are only 2 people who work part time (1 day a week). There were 2-3 others, but they all quit their jobs because school became too demanding. The stress of keeping a job, maintaining your studies, and doing well in school is not worth the small amount of money you will make (to me, at least). I'd rather focus on school and in my free time, I'd rather relax and mentally recharge instead of going to work.