If you are a developer worth your salt and not even registering on that scale, then I'm going to go with "Underpaid". Unless you live in like Bumstump, TX where you can buy a 4 bedroom 3 bath home on 2 acres of land for 60k.
Stackoverflow is largely based out of NYC, so their salaries are going to be based on that starting point.
The average developer salary in the US is $80K but when you start going state by state you can see that NYC/California/et al are throwing that figure WAY off.
Of course, if you're trying to raise a big family, the math works out a little differently.