Lowest 10% (starting teachers) are in that $30-35K range:
Somewhat mitigating the 10-month work year is the fact that I'm guessing most teachers work more than 40 hours a week during the school year. I hosted a MathCounts competition today, and all the teachers were sitting at tables grading papers. I'm guessing that if they weren't at the competition, sometime this weekend they would be doing that at home. But then, lots of other people work overtime as well.
Most teachers that have been at it for more than 5 years have earned their Masters. $50K for a mid-career professional with a Masters degree isn't anything to write home about. When its all said and done, I don't think they are grossly underpaid or overpaid.
Anyone who thinks teachers are overpaid is free to take advantage of the situation and become one.