Paying it all off in three years is ridiculously stupid. Invest the money and pay a good $500-$1000 a month on your loan. Pay it off like a house, over a long period of time. If you save up and invest well you'll have more money in the long-term especially if you lose the big law job.
You should keep ~$20k in reserve, but paying off in three years is not stupid at all.
As discussed above, it's a guaranteed tax-free 8% investment. Nothing short of wildly speculative investments is going to beat loan repayments unless you can refi to a much lower rate (which is usually not possible the first few years out of school). Also, someone taking out a full 250k debt load will owe $1.8k a month even on a 30 year payment plan. Can't do the $500 a month thing unless you are in forebearance or defaulting.