I have owned these speakers for over 20 years, the most important feature presuming they are in working order is to have the time alignment charts so they can be properly set up, they originally come with a protractor accurate to the 1/64th of an inch. and the chart is then based on ear height from the floor, and distance from ear to the middle of the top of the bass cavity. Dale has told me in some ways they are still better than his more modern day summit speakers produced as intuitive design. They were in the 15K range back in the early 1990s, at full price, I've no idea of their current value. I suspect many like myself left the speaker market once they got spoiled by these speakers.