I am considering selling my pair of Polk SDA 2B's. They are in perfect shape except for a some wear in the fabric. I have the original boxes and packing along with the manuals and the crossover cable. What I was interested in knowing is how much they might be worth and where would be the best place to sell them. I live in the Dallas,TX area, they are very heavy and would be expensive to ship very far. Any advice would be greatly appreciated.