The closest I have seen to this is speakers like the $40K Talon Firebird Diamonds that you can now get for $7K or so, maybe less, in perfectly good shape. They are every bit as capable as speakers made today, and will easily outperform speakers that sell for $7K new. Part of the reason they are so cheap is that Talon as a company doesn't exist anymore. If something goes wrong with them, you're on your own.
I recently bought a pair of Gershman Acoustics GAP-828 speakers, which are likely around 10 years old or so. Original list was around $15K, I paid $5K, and they were in perfect shape. One of the Dynaudio Esotec tweeters got a nice big dent while they were being unpacked, and I got in touch with Gershman and they sent me a brand new set. I also bought a set of midrange drivers to keep in reserve. This is why when buying older speakers, I think it really pays to buy from a company that's still around, so you can still get parts. I have one spare tweeter and two spare midranges ready to go just in case, and Gershman still has some of the original woofers left in stock should I ever need one. They can also be upgraded to the final GAP-888 spec ($24K list) for about $3800, which still represents a 66% off deal over new - and they basically would be new at that point since Gershman would put in new crossovers and new woofers as part of the update.
Good luck finding a speaker for $5K that can hit 22Hz like the 828s can, or that uses their "box within a box" construction, arced pyramid shape to reduce standing waves and diffraction, etc.
I recently bought a pair of Gershman Acoustics GAP-828 speakers, which are likely around 10 years old or so. Original list was around $15K, I paid $5K, and they were in perfect shape. One of the Dynaudio Esotec tweeters got a nice big dent while they were being unpacked, and I got in touch with Gershman and they sent me a brand new set. I also bought a set of midrange drivers to keep in reserve. This is why when buying older speakers, I think it really pays to buy from a company that's still around, so you can still get parts. I have one spare tweeter and two spare midranges ready to go just in case, and Gershman still has some of the original woofers left in stock should I ever need one. They can also be upgraded to the final GAP-888 spec ($24K list) for about $3800, which still represents a 66% off deal over new - and they basically would be new at that point since Gershman would put in new crossovers and new woofers as part of the update.
Good luck finding a speaker for $5K that can hit 22Hz like the 828s can, or that uses their "box within a box" construction, arced pyramid shape to reduce standing waves and diffraction, etc.