Trends in value of vintage / used audio equipment?

Recently have had 3 Onkyo Integra M-504s amps restored.  Prices are increasing on the usual suspect sites. I've seen what I could get for $450 go up to $1000. Not all meters that look great are blue.  And oh yeah, the meters do have a use. The new new mid-fi gear just isn't up to the 80s-90s amps in my opinion. However, I do like the new streamers and DACs that can be paired with about anything.

Carver amps have meters.  They are not considered high end but I love the way they sound.  I have 3, would buy more.  The TFM -35 and TFM 35x are excellent and priced around 500.00  worth every penny 

I have a Mac 4100. First solid state receiver they made. In a box after a factory refurb. I don't use it...wondering what it may be worth. ? I could use it to power my front two but just purchased an Anthem 325 to drive my ML ESL 11a's for that.  Curious?

OP

Good question, I’ve never found a source for price trends, my sense is that prices went up quite a bit during covid, stopped rising and have been dropping some during last year.

I occasionally glance at prices on hifishark of the many vintage pieces I have bought since 2019 on hifishark:

McIntosh mx110z tube tuner/preamp

Cayin A-88T Integrated Tube Amp MK1, 16 ohm taps

JVC TT81 in Two Arm Plinth PL-2

Sony xa5400es SACD Player

Yamaha CR-1040 SS Receiver

Mitsubishi Vertical TT LT-5V

Chase RLC-1 Remote Line Controller

Technics SL-J33 Programmable TT

Sony TT FL-1 Front Loading Drawer Type TT.

Also, when I read about exceptional vintage pieces I don’t own, look them up just to know about them, I sense the same ’way up/dropping some’ pricing trend.

Without a doubt, Meters both increase the price and hold their value, much like vintage cars, i.e. the (VW, TBird, Porsche ... ) Convertible version holds/increases in value far more than the more common and less special sedans.

Some Vintage pieces are well worth their reputation.

But i bought mine at relatively low price...

 Old gear need repairment or are at risk of...

Then the market of used gear can be overpricing them for sure...

 And we can buy  very cheap  and very good gear now (Chinese among other things) then most vintage pieces may be not a so much good deal...

But some stay because of versatility of the design which exist no more and because of the high quality of some mythical vintage (Sansui alpha for me)

I installed VU meter on my wife head and she look beautiful but it does not improved the sound ...

All VU meter i bought  were beautiful and useless ...