I have an HIS branded HD 6990 that I'd like to sell. Based on eBay prices I think 900 + actual shipping (or the equivalent in bitcoin at the market rate) would be a fair price but I might entertain offers if you PM them. The hard includes a dummy plug so that you don't need a monitor connected to it and can administer the system remotely.
If anyone is interested I can take a picture of the card with my username, the date, a sketch of a t-rex with a machine gun, etc. Ships from the US so if you're in the US expect shipping prices of around $10. The card weighs about 4lbs so if you want international shipping you can use that figure to calculate it.
I'm paypal business verified, an eBay powerseller (around 2k feedback) etc. I can provide these accounts and proof that I own them upon request. I live in Central Florida and will do local pick-up should anyone be interested in that, too.