The Great Wall only lists the clear plastic close up version that comes in 2 pieces.
If you are looking for a large stage version, then they are usually very expensive in the $500 to $1,500.00 range or more. I have seen several version on the Internet made of wood. Can't say who the person was that demonstrated it.
The clear plastic close up version is sold on eBay for $7.99.
Very puzzling, as you don't give any details, and post in the stage magic topic. So we can't tell what you may be referring to.
That video you are referring to could be just a, [b]Look See What I built[/b] video, like most of them. Does not mean they are selling anything.