Good post newmanineastTN. I would really suggest if you have good spots to dig in, let roots go to a minimum of 15-20 yo. I normally try and have the bulk of mine 25 and up. By doing this you get a premium price. As an example I think most diggers sold for an average of $450 - $550 last year, I sold for $650! Also take care to dig your roots right, break off nothing. Of course this is not always possible, but strive to keep as many of the hair roots as possible.
Also keep trying to find the best buyer possible. You've got to try and cut out the guy that is selling to that guy, who is selling to that guy, who is selling to that guy. Your buyer should be very happy to see the quality of your root and should treat you well for your quality roots.If he is not mentioning quality and age, find someone else.
Good luck!