Casio CZ/ VZ/ FZ - Pro Series

>Why does the cz-1000's and the 101's go for double what cz-1 sell for.
>Why does this happen?  Does everybody else know something about these
>boards that I don't?
>
>The cz-1 is a better synth-more stuff, more everything, even more
>keys.  Why don't they seem to sell as well?

It's probably because the CZ-1 is big and heavy in comparison to the 101 and 
1000, sometimes people value something they can stick into a corner when 
they don't need it.

It's been a while since I checked the prices but I seem to remember the 
DX100 similarly fetching more than it should.