I've noticed very high prices for quality used gear on Ebay. My Nakamichi 7A cassette deck I purchased for $700 in 1990 is now $1,500 to $5,900 averaging $2,500 (more than new), my Marantz 7T pre-amp I purchased for $150 in 1995 is now $1,200 to $3,000 with several in the mid-$2,000s, my Mac MC30s which I was given in 2000 are now $1000-$2000, my SME IV which I paid $1100 in 1989 is now $4,700 NEW (and being used on the latest SME turntable).
So, some high end older audio gear has vastly appreciated in the current market. I think speakers have dropped the most unless they are Tannoys or Altecs from the 50's and 60's. My Legacy Focus speakers sold today for $12,000 are not the same as my 25 year old pair which now resell for only $2200-$2500 (a bargain).
If I replace my speakers, I'm looking at $50-60K for Einsteins, Luminwhites or Von Schweikert VR55Ks. That's high end dollars.