Well, I found a couple of places around me but they were specialty joints. I wonder if Whole Foods grocery store has it. Do you have a Trader Joes or Whole Food Market around you?
I have no idea. I have one that is aged 35 years but it was a gift from a friend who lives in Modena, Italy - home of balsamic vinegar. I should think a good specialty store would carry it though. You might even try the Italian area where you live.