>Hundreds of dollars for an antique long out of production seems extremely reasonable to me. I'm not sure what you were expecting, $10?
No, it's just that the supply of old synths in general appears to exceed the demand, but because there is this idea that old synths are valuable, people are willing to sit on them with high listing prices instead of adjusting their prices to move them. It's not really an efficient market and it's frustrating.
It's also a pretty substantial object. They have a metal case! It's quite a large and heavy thing to ship and store.