Why the difference in resale value?

Hey out there.  I do appreciate all the perspectives coming from everyone.  It was fun - for a relative 'snoozer'!  Maybe I can spice things up a little.  So, "Fuzztone," you wonder why should I care in the first place.  Well, maybe because I would be looking to differentiate among historically well regarded yet affordable products of the same class currently on offer in the resale marketplace.  Or maybe I wouldn't, but I simply would want to see what you and others would have to say on an audio related topic of my choosing.  Or how about this even...it was a round about way of calling out those who must seize an opportunity to gain at the expense of the guileless, whether it be with audio sales or with auto sales.  Ebay audio sellers take heed...Sorry, but no way am I giving you double the original retail price for a 30+ year-old metered power amp, while I couldn't in my right mind ask for more than maybe 70% of original retail, at best, for a similarly priced and respected functional "black box" equivalent from back in the day.  Sell 'em if you got 'em - just not to me!   

@rwp2964u 
  👍

Probably just supply. Why would anyone actually care?

"Actually" ?

Let me help. Because this is a friendly discussion forum where the bar to ask a question is reasonably modest?

Well since the market sets the price, the comment "opportunistic sellers" is just plain silly. Obviously demand for one is greater than the other. Number of units produced could have some bearing.