Big Law can be, I'm surprised at how generous the benefits package is. In fact, I think JAGs tend to underestimate them. While Big Law is now $180K plus bonus, if a JAG worked in a location as expensive at the Big Law cities tend to be, I think the compensation comes out not too far behind. For example, if an O-3 is working in San Diego I believe you'd get a little over $3000 for housing/month, untaxed, which would roughly be the equivalent of 50K considering the high tax bracket Big Law lawyers are in. I've heard the average family spends 20K for health. Service members pay very little if anything for health care. Again, those are direct savings that would normally come out of taxable income, so that would roughly be 25K. Then you add significant tuition assistance, which can easily save a couple thousand/month given how expensive law school is nowadays. And, of course, there are just lots of other little things like Space A, base exchange, food allowance, etc. that go a long way. Finally, there's the income, which isn't that high, but it's also not taxed that high, and you'll generally spend much less on state income tax than you would in a Big Law city. At the end of the day, over the course of a career I'm sure a JAG makes less than Big Law, but given the Big Law hours, it seems like more than a fair trade-off.

tl;dr for prospective lawyers. Join the JAG Corps.