That's the game industry for you, a few franchises make huge money, everyone else is struggling at best.
There's no answer for that. It all depends on location and job position. For example it's really pricey to live in California area, less in Texas, still less in UK, even less in Finland (Max Payne, Alan Wake developers Remedy or Flatout developer Bugbear) and still less in Poland (The Witcher developers CDproject). Entry level programmer can barely pay his rent and buy food while Lead Progammer get big bucks.
For example the salaries in Nightshapes linked list are way too high. If entry level progammer would ask 50k here in Finland, he'd end up with the permanent smile on his face in the nearest river.
Actually Texas is a pretty cheap place to live, I believe that applies internationally among first world countries as well.