I've been holding on to this in case I ever pull my onkyo m-504 out of my home theater but I doubt it will ever happen. This is a great no-nonsense preamp. I've read reviews where it is compared to preamps costing much more.
For more info, you can download a manual here:
http://www.retrevo.com/support/Onkyo.../365bh139/t/2/
The outer cap on one of the RCA jacks for the CD input was missing when I bought the unit. It did work this way but I recently took it to a local shop where they replaced the CD jacks and went over all the solder joints. Everything is functioning perfectly. There are a few scratches on the case, I can post or pm pictures if there is any interest.
Regarding trade value, I've seen these sell on ebay in the $200 range. I'd love a cheapy 5 string to convince myself I don't need to buy a nice 5 string but I'll consider anything. Whatcha got?