Amazon.ca wrote:

We’re sorry to report we won’t be able to obtain the following item from
your order:

Luigi Serafini “Codex Seraphinianus“

Although we’d expected to be able to send this item to you, we’ve since
found it is not available from any of our sources at this time.

Oh, well — that’s what I expected. The past existence of an inexpensive
Codex in Random House’s catalogue intrigues me, though. I’ve never seen
it on eBay or through abebooks.