Most hatchery EEs do lay blue/green. I honestly don't think people who are buying pure AMs are in it for their blue eggs. If they are willing to pay more money for something pure, they are likely in it to win it, in a sense. But it seems that most people who buy EEs as Ameraucanas are quite new...
Was it spelled Ameraucana or Americana? Americana is just a fancy name for EEs that a lot of hatcheries will use. And yes, some do sell EEs as Ameraucanas too. I don't think it's a way to gain MORE money, EEs are just so much easier to find.