Best value in pre-owned preamps right now?

A few that come to mind....

SAS Audio preamps. Owned a 10A linestage...very good product if you can find one. I haven't seen one up for sale in years, and I'm not sure if Steve Sammet is still in business. Can't go wrong if you want to hear what a really good preamp can do for your system.

YS Audio A2. This one never gets much attention but it's a serious contender even bought new, and used it's a steal. I don't see this one come up used very much either. I'd have to spend much more to do significantly better, especially with upgraded caps and vintage tubes on deck.

Juicy Music preamps. I was just listening to a Blueberry at friend's house just a few hours ago...always impressive and extremely musical from top to bottom, with a top-notch phono stage to boot. That's a good one to snatch up if you find it.

Mmm depends on your budget as this is all relative. My picks would be the Audio Research Reference 5 if you want a tubed preamp & Vitus RD-100 if you also want a good dac. They can be found had $6k 2nd hand. The Ref 5 can also be upgraded to SE spec later & tube-rolled if you wanted to take it further. But if you're after a pure ss linestage, the Vitus RL-101 is amazing for the price & is based on filter down technology from the Signature and Masterpiece series.

.
My vote goes to the Audio Research Reference 3.
Right at $5k and sometimes a little less, it is a stunner.

The new Reference 6 is $14k.
.

Another vote for the Modwright. Best pre Ive owned.

Spectral DMC-10. Particularly if you need a phono preamp. Forget the DMC-6. All Class A discrete design with a real tape monitor loop. Blindingly fast. No remote. Manual volume control an input selector only.

You can probably find one for under $1500.