Unless it's still new and wrapped up in plastic, in my opinion, you are going to take a loss on it. There are some definite exceptions with some of the more rare pieces. EL cased panerai's, WM9 sub's, etc. But for the most part, I would say there is going to be a loss. I always lose money on watches that i sell. I basically consider it a "rental" fee for trying out the watch
BTW - if you are talking about a trade for one of those McIntosh Pre-Amps you have, then you definitely do not want to do a deal that gets you less than what they are worth. Never sell vintage McIntosh at a loss.