I keep the block version as the "lens cap" on my D850. It is ideal for snap shots, especially shut down to f5.6 or f8. This is the only copy of the black version I've seen, and it was a stiff price for what it is, but not in the stratosphere. If one is patient, a silver one can be found, which is my experience in the UK.
And they are in demand, probably why this dinky prime is still expensive!
"The AI Nikkor 45mm f/2.8P was introduced in 2001, the same year the FM3A was released, but was discontinued when FM3A production ended due to the rapid rise of digital cameras. It had a relatively short life. One of the reasons for this was likely that at roughly ¥50,000, the kit containing the lens, dedicated filters and hood, and pouch was relatively expensive. As a designer, I find this disappointing."