I spent a great deal of time inside the Diamond Horseshoe and listing everything that was for sale would be difficult.
There was left over merchandise from the previous evening's Room For One More Haunted Mansion Event. This consisted mostly of pins and pin sets.
There was the non-limited 40th anniversary stuff designed by Kevin Kidney and Jody Daily. This included the vase based on the Grand Canyon Concourse mural in the Contemporary, small world plates, cell phone covers etc. This stuff is available in the Art of Disney. I believe it was available there because the artists were going to be there.
There were a great many boxes of 40th anniversary tshirts.
There was a long table set up so Noah (an artist) could display his artwork and meet guests for autographs. His art was mostly larger gicleed canvas.
Also inside, but inside a roped off section, were the various limited edition pins. pin sets and the very limited edition $600 nine inch Vinylmation. I believe there were 6 of these, all together. From what I could see, this was metallic purple and looked like someone wrote on it with a sharpie. I was told the $150 three inch version sold out very early.
This section was roped off and only accessible by waiting in the line for folks with wristbands or waiting in the very long and never moving stand-by line.
It's also my understanding that all of the unsold limited edition pins, pin sets etc (including left over "I Was There" pins were sold the next day at the Frontierland Mercantile.
I don't know that I can offer any more detail than that