I’ve been lucky in the last few years with "Vintage" Audio Gear. My BATVK50-SE that I bought "as is" from TMRaudio ran great for 2.5 years until a power surge at home while I was out took out the power supply. $1800 including shipping both ways from BAT in Maryland and it’s like it came out of the factory in 1999 but better !
Now I can't sell this amp because of what I have tied up in it but nor do I want to. I’ve tried other Preamps through my rig and they come close but the BAT still wins both on audio quality and conveniences. The SPL Preamp came scary close but the BAT won IMHO overall. The Black ICE F360 & ARIES are great Preamps (again from Maryland) and I use the ARIES in conjunction with the BAT and they works great together. I have the option to just use the BAT by itself for critical listening.
My DAC/Transport is the now 10 year old PS Audio Perfectwave & Directstream MK1 designs and runs great. My Klipsch Cornwall IV’s were 2nd hand and in mint shape. I blew the Tweeters last year and Klipsch helped me out thanks to the remainder of the factory warranty.
My PS Audio Stellar Phono also used has no issues after 1.5 yrs. ownership.
Linn LP12/Lingo/Ekos/Benz Micro Cart. also used (circa 1989-1990) has no issues and was recently serviced by the previous owner. Again, no issues.
Onkyo PR-SC5509 AV Preamp also purchased used. No issues.
Brick & Morter retailers who missed out on internet selling early on haven’t survived and those who have. Either did reap the advantages of online sales while keeping a physical presence or have a very loyal customer base.