I wrote that post you quoted VERY tongue in cheek. They are not all that valuable in reality, Doomy's well known for overestimating anything he reckons is good. Maybe I should have sprinkled the text with lots of smileys.
What someone wants to pay for it is its value for the day.
Personally I dislike the A2000 cherry keyboard, since it has a different layout than most other Amiga keyboards. Small function keys + gaps between alt+amiga and space. There are also slight timing differences because they use Philips made keyboard controllers, unlike all other Amiga keyboards, however you probably will never encounter any software that would fail to read the keyboard.