One thing that may be worth considering is that the lowball salaries at the top schools (like 40k out of GSB) are probably people who went into nonprofit or entrepreneurial roles. A lot of people also choose to sacrifice pay for lower income jobs because of their particular passion.
Also, if you keep in mind that the average signing bonus coming out of a top 10 school is around $20k, with proper money management you could probably have half your loans paid off in the first year. If you have $80k in debt and get a 20k signing bonus, and have the self-discipline to apply that bonus to your debt, voila! they're 25% reduced, and you just shaved several years of payments off.
Basically, rather than looking at ranges and considering the worst case scenario, consider what job you really want to have coming out of the program. Do some research and figure out what that job generally earns in the areas you hope to live (particularly for career switchers, it should be pretty straightforward to get a reasonable range for an entry level with an MBA salary in any standard field), and review your school's numbers on various careers to get an idea on the salary range for that career for your particular school. Most schools have pretty extensive breakdowns in their employment report of salaries by job function, industry, region, etc. Keep in mind that if you're a career switcher, you'll be towards the bottom of the range for your particular field (not necessarily towards the bottom of the overall salary range, depending on the career you choose) and if you're just augmenting your current career, you're likely to be towards the middle to top of the range. But don't consider the $40k nonprofit salary if you're definitely not going into the nonprofit sector. Similarly, don't assume that you'll earn $150k as a consultant without any experience.
Obviously, if you're interested in entrepreneurial work or the nonprofit sector after school, your mileage may vary, but keep in mind that a lot of programs also have loan help programs for those going into government or nonprofit work.
And, as several folks have mentioned, your MBA is an investment. With a couple good bonuses (even normal old bonuses, not the astronomical I-banking bonuses), you'll be amazed how quickly you can pay off the debt. It's definitely, definitely worth another close look before you give up on your dream school to avoid the debt.