Is this Antique Russian Aerial Spy Lens Worth $400,000?

It's not uncommon, a unique or rare piece of photography gear pops up on eBay for an extreme price every now and then.  It was originally listed at $488,000 and the seller has kindly dropped the price to $400,000.

With the auction written in half-broken English, it's described as a "UNIQUE ANTIQUE 400mm AERIAL SPACE Lens LARGE FORMAT SPACE CRAFT AIR FORCE LENS", and the buy it now price is $400,000 with no option to bid.

For that, you get a 400mm f/4.5 large format lens, which is apparently derived from German Zeiss lenses, but " CRITICALLY UPGRADED to COATED PRECIOUS GLASS".  It even comes with filter and a cap.

While it does seem like this is a genuinely rare lens, that price does seem a bit astonishing. In the Q&A, someone who owns one themselves calls out the seller, claiming that their model (which is allegedly in even better condition) is valued at £8000 (around $12000). To which the seller replied "MUSEUM EXHIBIT... HISTORICAL RELICT... I DEVELOPED THIS PRODUCT FROM STRAY UNKNOWN LENS."

The seller also claims to be the actual ex-USSR photo expert with a master degree in philosophy and liberal arts.  It will be interesting to see if the seller will continue to drop the price if no one takes the bite.