Agree with Buconero, but it's even worse than that. In the description of the blue book methodolgy, if there aren't any comparables, they make some up, based on "similar" gear, as if it were interchangeable.
I just threw out some 14-year-old speakers that had foam surrounds that went bad, the drivers were no longer available, and it was not cost effective to fix them, anyway. Based on this experience, I am not interested in old speakers. There are parts of a stereo that can last a long time, but rarely speakers. Besides, it's one of the areas where technology really has marched on, and is arguably the most important part of your whole system.
I just threw out some 14-year-old speakers that had foam surrounds that went bad, the drivers were no longer available, and it was not cost effective to fix them, anyway. Based on this experience, I am not interested in old speakers. There are parts of a stereo that can last a long time, but rarely speakers. Besides, it's one of the areas where technology really has marched on, and is arguably the most important part of your whole system.