Wait a few weeks. I have found, believe it or not, you have a better chance to get the same selling price if you wait for the person who wins this auction to save a little money so he can buy yours too. I.e. people who pay top dollar for one rare specialized item will buy more than one if given the chance.
I asked a friend who I consider the most knowledgeable on the PC soundcards / plastic micro sound chips / early game system soundchips about the adlib Gold 1000. He said he was watching it as well and doesn't understand it, he figured $50-$100. He suggested that maybe someone is trying to push the market up on them, the only reason I could see that is if someone is sitting on a bunch of NIB ones from Adlib going out of business. At the end of the day though, it's an early sound card and I couldn't find another example of one on eBay so it seems to be rare. Supposedly some DOS games supported it's extra features so that makes for a good case for it being desireable. Fascinating to watch, perhaps there are collectors trying to get them all in the box and that card is the rare one. I have none of them in the box but I still have my Sound Blaster 1.0 w/ CMS chips, Gravis Ultrasound ISA and PCI, and an Adlib card I put in a Tandy 1000 system I gave to a friend (the flyback on the CM-5 or CM-11 went thermonuclear on the monitor :-( Guess I should buy a MT-32 soon! - Ethan