Try putting the Bose on ebay. Just put a reserve for the lowest amount you're willing to take. Chances are you'll get close to what they are worth on there. If they are a special edition (though I'm pretty sure you could buy the black laquer finish 901s here before), they'll sell for a premium over the regular 901s.
If you prefer a local sale, try audiogon.com or craigslist.org. You probably won't get as much on these two as ebay though.