Id go on ebay with something like this.
I had considered that, but really wanted to support the Bitcoin economy with what I felt was a somewhat novel trade offering.
The problem is for deals like this, eBay is and will likely always be the go-to place. Craigslist *might* also be an option, though that's really hit-and-miss.
Keep in mind that for all intents and purposes, Bitcoin is still in an infant stage and most people here would be more interested in buying to resell, not to keep/collect.
That does seem to be the case. It's too bad really. Still, Bitmit might be a viable option perhaps, though I'd loathe to individually post all of these cards.