I think you have ti understand what might be happening with the prices on Alamo posters
When something starts getting collected, it commonly starts at a slow pace as collectors feel their way around in any particular "new" area such as Alamo posters.
Well, you get collectors who suddenly start wanting all of them, and they begin to compete, slowly driving up prices. Then at some point, two or more of the collectors with deep pockets (well, usually deep) starts getting real excited and begin driving things up very fast as they get the emotional part of collecting (I gotta have it.. I gotta have it.. I GOTTA HAVE IT NOW!!!!!!!) and at that point, any rational thoughts that were earlier attached to what they have to pay gets thrown out the window and the concept of "if other people are willing to pay such a price, I have to be willing to pay an even higher price and the prices the other collectors want to pay shows that the sky is the limit because there is price support!"
You see that happen with "new" posters that seem to be scarce or in high demand, like Brokeback Mountain posters were. (not comparing them to Alamos, which are way better posters)
Then you have to add the clear fact that #1) there are limited numbers of the posters and #2) increasing numbers of collectors.
So you have all of the pertinent factors which drive a market present at one time. I don't know what will happen in the future (whether Alamo posters will see continued price support). But it is a possibility they will.
