Check the prices of new first. What you paid is irrelevant. For example, with an easy Google search right now, 12-9-09 yoiu can find Ultrasone HFI-780s for $189, brand new, including shipping. Denon D2000s are selling for $214. New, including shipping. Want to make your used stuff...

OK I had a pair of Sennheisers that I thought were great back in the 80's, but I haven't done much with headphones since. I've been listening to my music on my home theater system - a Denon AVR-4802R, connected to Polk Audio RTi-A9s, with CSi A6 and FXi-A6 rounding out the 5 channel setup...