How does this sound

Still in search of a great amp for under $1000, I stumbled across an older Marantz 250 with the gold anodized faceplate. The seller is asking for an $800 purchase price, but the thing is, the amp was never used! The box was opened, but it is still sealed in the original plastic bag. Does anyone have any idea how this amp may sound, or approximately what its worth? Thanks a bunch.

Oh, there was also a Bryston 3B-ST for sale. Any opinions regarding this amp? (I was outbid on a rather nice Aragon amp last evening :(