Can you prove that chicken was happy till the last day, or that it wouldn't have been happier in a confinement, with antibiotic usage?  No.  

You can't say that it's better quality, because there's no proof other than perception. Your price for a sold bird doesn't mean it's quality, it just means that the customer is willing to pay that much for what they percieve to be better.  Regardless of what may or may not be better, they percieve it as better.   Organic isn't necessarily better, nor is free range, or antibiotic free, but certain people's perception is that it is, so they pay more.  That's their choice.  I choose to eat what's cheap and I've found to be just as safe and healthy.  

The quality line is bull.  I've driven past a field of organic beans a few times this week, I can't tell if he's seeded waterhemp, ragweed, and button weeds, or not.  You can't tell me that when that is "quality."  There's going to be all sorts of weed seeds in the grain sample.  It's going to take twice as long, if not longer to clean and process.