You'd be cutting your pay to $45k ($60k annualized), working less, getting an extra couple months of vacation, and great pension benefits.
I also forgot that for teaching 5 years, you've just earned a pension of 6% of your "Final Average Salary" (average of your last 3 years). So for teaching 5 years, you've just earned a pension of $2900/year (inflation adjusted) starting at age 55 (assuming the 5 year pay is $50,000, not sure I understand the table I posted). Assuming you live to be 80, that's worth another $15k per 9 months of work.
So teachers total comp is $60k per 9 months, just starting out (equivalent to $80k/year). That's really not bad for entry level.
http://thebronxislearning.blogspot.com/2008/10/nyc-teacher-p... (You need Readability to view that page.)
In finance, you are working far more hours than the teacher, and you can also be fired whenever you under perform. You also seem to be assuming that GS or JPM will give a job to just any idiot with a math degree.
"How little can we possibly pay to keep a warm body in teh room"
Not what I said at all. I said "fill our open positions" - in general, to fill a position, you must find qualified people. I'm a strong proponent of measuring performance, firing the warm bodies who don't perform, and offering rewards to those who perform well.