I've been keeping an eye on eBay and am curious why trumpets get valued as they do. This link Vintage Olds Ambassador Trumpet | eBay is for an Olds Ambassador. The Ambassador seems to be in demand. But this horn, which has "good" serial number and appear to be in decent condition didn't get sold (the original listing bid up to $46; this link is a re-list) Can some one give me some insight as to what clues to look for when buying a trumpet on eBay? I'd have bid on this one, but minus any information on playability, I was watching for other bids before I made mine.