Agreed. The instant the CCS1 adapter becomes (and reliably stays) available, the CHAdeMO price should fall. Maybe. But not yet.
I bought one new from Tesla, never used it, and sold it for what I paid to someone who (allegedly) wanted it for a friend in Hawaii where CHadeMO stations are more available than SCs on some islands. Or so he claimed.
That's the thing. I hear of free CHAdeMO charging stations (not near me), and (outlying) rural places where there are more CHAdeMO stations than Superchargers. For those locations, a CHAdeMO adapter will remain desirable, for now.
But I think that
this is maybe a tad excessive:
$12,000!
A true (eBay) auction for a discontinued item that ends up exceeding the original retail price is one thing. But to flat out ask for that amount...? (It does come with the protective $20 nylon gun case and "a couple of scuffs," though.)