Yep - plus resell values are always much higher after things first appear on the secondary market (I guess a combo of people frustrated they missed out and who are desperate to get them and people who have enough cash that they don't care about the prices). On the other hand, $500 is not too obscene for 3 screen prints, these versions are signed and because they're for Star Wars, they should keep their value.
I think I've convinced myself not to bother though, realistically they won't make the wall for quite a while and for $500, I could get some really nice paper that I've been after for a while. Also, he just tweeted to say he'll put the link up in an hr and I can't be bothered to sit at work and wait!