Well, that card runs for about $15-$20, so I'd put it at around 7k-10k credits. It's really up to you, but if you try to get the most out of it (for example, some people think 1k-$1), then it's very unlikely you'll find a buyer. If you set up an auction with a starting price of 7k, I'll definitely bid, and I bet other people would be more willing to put credits on it.