I may have met you during my GULC visit in April. (Or met someone with the exact same dilemma lol)
This might sound crazy, but cost and debt load should actually matter less for someone committed to PI than for someone committed to biglaw/private practice, especially at schools that have LRAPs tied to IBR/PSLF. Because LRAPs cover all or part of the loan payments for graduates in PI/govt, your out-of-pocket cost would likely end up being the same regardless of how much debt you incurred.
To illustrate this point, let's compare what your loan payments would be out of GULC vs what they would be out of NU. We'll assume that you'll work in PI/govt for 10 consecutive years and use LRAP with IBR/PSLF to manage your debt. We'll also assume that your debt out of GULC will be 170k compared to 130k out of NU, and that your income will hold steady at 65k over 10 years. (I know, the last thing is a wacky assumption, but accept it for the sake of simplicity)
I got the following scenarios from the TLS Guide to LRAPs and adjusted the calculations to reflect your estimated debt from each school. (
http://www.top-law-schools.com/tls-guide-to-lrap.html)
Georgetown
An unmarried graduate.
Salary: $65,000
Salary less Taxes: ($65,000 - $12,438) = $52,562
Law School Debt: $170,000 on a ten-year repayment plan at 6.8% interest
Yearly Debt Obligation (on a ten-year repayment): $23,476
Yearly Debt Obligation under IBR: (($65,000 – 1.5*$10,830)*.15) = $7,313
LRAP Award: $7,313
Graduate’s Contribution: $0
Take-home Income: $52,562
Northwestern
An unmarried graduate with no undergraduate debt within five years of entering the program.
Salary: $65,000
Salary less Taxes: ($65,000 - $12,438) = $52,562
Law School Debt: $130,000 on a ten-year repayment plan at 6.8% interest
Yearly Debt Obligation (on a ten-year repayment): $17,952
Yearly Debt Obligation under IBR: (($65,000 – 1.5*$10,830)*.15) = $7,313
PSFP Award: (25% of $7,313) = $1,828
Graduate’s Contribution: ($7,313 - $1,828) = $5,485
Take-home Income: ($52,562 - $5,485) = $47,077
Not only does this demonstrate that total cost/debt is largely irrelevant for applicants committed to PI, it also demonstrates that the strength of a school's LRAP could be the most important financial factor in your decision. If these scenarios remain constant for 10 years, Northwestern would end up costing you $54,850 more out-of-pocket than Georgetown, despite the fact that you were in $40,000 more debt at Georgetown.
There are, of course, a number of downsides to racking up more debt, even if you plan to use LRAP with IBR/PSLF. You might change your mind during law school and decide to pursue biglaw, or you might work in PI for 5 years, burn out, and move into the private sector where you won't have the LRAP/PSLF safety net. There's also a chance that you won't be able to find a PI job and will get stuck paying down all the debt out-of-pocket. And finally, the more debt you're in, the tougher it will be to get a mortgage for your first house.
Nonetheless, you should consider that for someone committed to 10 years of PI work, GULC would likely be a much better financial investment than NU, even if it means incurring significantly more debt. Of course, this is just one factor among many and you'll have to evaluate a number of things that aren't easily quantifiable: the strength of your commitment to PI/govt work, the chances of getting an LRAP eligible job from each school, your comfort level with significant debt, how happy you would be at each school, where you want to practice etc.
Good luck!