This question gets asked a lot and it all comes down to weird market timing. There is no real reason why a certain product will have a lot of used "for sale". That being said, I have heard this amp. It's really not a bad amp for the money you are spending. Good resolution and neutral sonic signature. There are better amps, but of course much more expensive.
If the PS Audio Stellar 700M is as great as all the reviewers say....
...why are there so many used ones for sale?