.. there was no price shown on the model page, so I clicked "order".
After entering my address, I got to the "order details" page, where there's a "material" dropdown. It didn't have any entries in it, so I couldn't get any further with the order.
We've deliberately made this object impossible to order - it's size is almost five meters wide so it's rejected by the ordering process. This was a bit of a hack - we really wanted to showcase this object, but the artist wanted to be sure other users couldn't order it. There'll be a better function for this in the future!