If various articles I've seen on the topic are to be believed, eggs from pastured hens don't just look and taste different—they're far more nutritious than the rest[1]. I forget which nutrient (and I'm not certain it's even one of the ones listed at that link) but IIRC there's one that's very difficult to come by in the recommended quantities unless you 1) eat lots of insects, or 2) eat eggs and/or meat from birds that eat lots of insects. As one might expect, it's almost completely absent from non-pastured eggs.

See also declining nutrient levels in produce generally[2]. I'm becoming increasingly convinced that our ultra-low food prices, especially the US, amount to a scam.

We've got year-round variety (shipped from hundreds to thousands of miles away), we've got quantity, our produce is colorful (though bland), and our food rarely makes us sick (very nice, to be sure), but if you seek out quality there go convenience (distant 1 day/week farmers' markets versus a dozen nearby supermarkets that operate 24/7) and low prices, plus you've got to remember all the labeling and advertising tricks of the sort mentioned in the article so you don't get screwed.

[1] http://wholehealthsource.blogspot.com/2009/05/pastured-eggs.... [2] (PDF WARNING) http://www.drapsley.com/Documents/Mineral%20losses%20in%20fo...