Speaker depreciation: Is there a rule of thumb?

I have noticed that the depreciation in addition to age is size and brand dependent. Big unknown speakers you are lucky to get 50% more likely 30% of oringinal msrp. Small easy to ship speakers from a well liked ,popular brand, you see a lot of people asking for as much as only 30% off of msrp, just the opposite.

popularity rules hear. buy used and avoid the pain.

Markphd makes a good suggestion in my experience: Follow the listings for a while. I have found the AudiogoN blue book to be generally high in average price. I am currently watching the Sony SCD-1 market, and missed a good one because I had not updated my email address on AudiogoN so the seller missed my what-would-have-been-winning bid.

db