On the "theater-used" part, we explain that all posters we describe that way were either printed used in theaters or were printed for theater use (as opposed to any kind of repro or commercial poster). There would be no way to determine if an excellent condition poster WAS used in a theater (and of course, anyone could make one appear as if it had).
On the set, Mark, I agree that in a dishonest auction, you would have surely paid more, because once you entered that higher amount the auction house would have mysteriously found an underbidder to make you pay near your maximum.
But had WE listed them as a set, there would have had to have been someone who was bidding over $1,000 for the set against you, and given that NO ONE (including yourself) made the effort to try to get them all, I think that is very unlikely (but of course, no one knows).
On whether they are a good buy or not, it is the same as with all rarities. If bunches more turn up, of course they will go for less. But if the others were trashed, then I believe these will later re-sell much higher. Time will tell.
On the prices, they seem good for year old posters. You guys created the $300 per poster expectation out of thin air.
Myself, I think the first one sold too low! Mark, if you want, I will give you $400 for it tonight (and I will give it to a supremely dedicated HP fan), The offer is only good for tonight, because tomorrow I may be able to get it from Thierry for $10!
Bruce