Its one thing to try and make a quick buck, its another to gouge. Doubling the retail price on a 6990 is beyond ridiculous, considering there are other alternatives for a lot cheaper.
And with that attitude, little alone the price, I doubt you'll get anyone to jump on this.
Oh and just doing a quick search:
http://www.eworldsale.com/sapphire-radeon-hd6990-4gb-ddr5-dvi-4x-mini-displayport-pci-express-video-card_8819_60405.htmlAt the time of this post is in stock for $800