I also posted this in the Triple Bill authentication thread, which has a link to my authentication of this poster.
I talked to this guy a couple of weeks ago. It seems to be the real deal. I told him to consign it but he thinks he's going to get $15,000 for it on Ebay and doesn't want to pay a larger commission. I think he's dreaming. The ESB "international" poster only sold for $1,800. Don't see how he could get more for this one.
Yeah, like I said in that thread, I just don't see it. Especially since it's dry backed. And on eBay. And local pickup only. And he makes it clear he set it at a very high reserve. Half of his description is basically designed to scare people off from bidding.
The other main problem is that there is really no precedent for historical prices. It's so rare, and so uncommon to ever come up for sale, that it's impossible to tell how much it could go for. That's a double edged sword. If there was no reserve, I could see a couple (or more) bidders getting into some war and it going up to a few thousand, but that's it. IMHO, he chose the worst possible venue for selling it. He thinks it's worth a ton, but is too greedy to try and sell it at a place that would realize the best possible price.
Based on the pics, and the limited authentication information (your site, starwarsmovieposter.com), I think it's legit too. But there are some concerns. This poster was supposed to be done on a very thick cardstock, and it looks practically mint in the pics. Why would someone have backed it with paper? And the seller went into so much detail about the history of the poster in general, but left out any specifics of how he acquired it.