Strangely, it seems neither the commentator on that website, nor the commenters there seem to get the gist of the plaintiff's argument. From what I can tell, it seems that their argument isn't that EA's overcharging because Next Gen costs $60 as opposed to $50 from previous gen. Their argument is that,
at one point, EA dropped their last gen prices from $50 to $30 when they were competing with NFL 2k5's $20 price tag. Then, according to the article on Gamepolitics, the plaintiffs filed a suit "alleging that EA used its exclusive licensing deal with the NFL to eliminate Take Two Interactive’s competing NFL 2K series. The suit charges that EA then exploited the resulting competitive vacuum to dramatically raise the retail price of Madden."
I don't know how strong the suit is, but it does make logical sense to me. It's not just a case of people being annoyed at Next Gen prices. EA proved that they could make a profit when slashing prices by $20, just not as big of one. So they bought out the NFL license to ensure they wouldn't have to lower prices in the future. I'm far from an NFL 2k fan (the only one I played was a rental of 2k5 and I hated everything but the ESPN license integration), so I never cared too much about the exclusivity license. But this is an angle I've never really thought about before.