Rega Osiris, new POS. Broken out of the box. Rega said it was within spec. For a garbage piece of gear.
CJ Premier 140. Use, broken. Got repaired and upgraded. Worked great after that.
Mcintosh Preamp. Forget the model. C40 or something. Used Broken. Told its within spec and to pound sand. Later met someone who knew the issue and said most tech weren't smart enough to fix it.
Audion Black Shadow 845. Used. Don't get me started. POS. Still has issues.
Rogue Audio amp. Used. Worked fine.
Dartzeel NHB 108. Use. Worked fine. When I sold it it went to Herv and he did about $750 in repairs. It needed some TLC but was not failing, Yet.
Found Music Blade amp. New. No mechanical issues. Still trying to get it to blend with my system.
Anyhow, my experience is used is a total crap shoot. I don't buy used anymore. Not unless I can see the piece. Or I know the seller. I don't know. Maybe I would. but its a risk. It is what it is. Old and used. Then again, I have friends that have been burned by a dealer buying new and there are issues that take months to fix. They are out $tens of thousands and have no equipment to play till the plant decides to fix their problems.