Yeah, what Arth said about trying to find a buyer for BB stuff is accurate, I am in the same boat as you, with an inactive account full of teir 1-2 BB fams and have been looking for months to find someone to cross trade without luck.
I would suggest trying the BB forums. I have had a few hits there, but most of the people who went back to BB don't have anything decent to trade for on their FF accounts anyways. I am about to the point where I am going to liquidate my account for horns and trade them accross. I wish you better luck!