I closely follow the used market for brands I like. It's kind of an obsession- probably from my years as a futures trader. Here's my take:
2020 COVID EIDL and PPP money gave a lot of people who don't handle money well a lot of buying power. Things that should have stayed cheap got stupid expensive. Those stimulus dollars left the weak hands and went to the strong hands. Now the weak hands find that lowering the ask is the only way to get a bid.
For at least 3 years prices have been dropping. The time it takes to sell is expanding. The market is slow and slowing. December-Feb are peak value selling months and once spring comes HiFi slides further.
Sellers hallucinate that there must be a greater fool out there somewhere and price their gear at 1/2 or more of retail. The truth is that 1/3 of retail is the figure that gets the buyers cash into the seller's hands.
Some premium gear holds value better than others. McIntosh- love them or hate them, has the best resale value. I don't know why exactly but they do. PS Audio gear-which is excellent has poor resale- mostly because Paul MsGowan keeps running specials that depress the resale market.
My beloved ARC gear is slouching toward Gomorrah as well. I had a seller beg me to buy his Ref 250 monoblocks that he listed for $8000 for $5,500. I passed. Ref 75s are now offered at $3500-$4000. The Music Room will pay $3000 if the units are mint. Ref 5s are offered in the fives and can be bought in the $4000 range if the seller wants it gone. In December 3 units hit the market with ridiculous asking prices. This will slow the market even more. Interestingly many of the items for sale have been offered well over a year. Some guys offer an item over market that they really don't care to sell and will run the ad for many months to even years. I see that a lot.
There is another factor that's difficult to quantify: Typically sellers made their purchase choices carefully and paid dearly for their prize. Many hours of bliss were spent listening to music and admiring their gear. They love their gear and it's a personal affront to them when a wise buyer makes that fair market offer. It hurts to sell in this market. Sadly, reality is cold and uncaring. As a seller the buyer is in control of the price. Sellers who don't understand that the buyer controls the price will have a very hard time selling as their gear continues to slouch in value.