Used tube preamp $2-3K

+++1 for Aric Audio Super 6SN7 ($4,000) or Motherlode II ($5,400) and for Don Sachs/Lynn Olson Raven preamp ($5,500). 

I have never heard one in my own system (only in a fellow hobbyists), but the Supratek preamps are also excellent. They have a bunch of models from $2,500 to $6,000

The Backert Labs Rhumba Extreme (NOT the base Rhumba as it it not in the same ballpark in SQ) is also a great preamp at $8,500, as is the the BAT VK-80 at $10,000

I personally prefer 6SN7 based preamps (Aric Audio, Don Sachs/Lynn Olson, Supratek), as they seem to match my tastes best.....but the Rhumba Extreme and BAT were excellent using other topologies.

I tested all of the above preamps except the Supratek, and in the end purchased the Aric Audio Motherlode XL. I have since heard the Supratek Cabernet, and it is excellent as well.

I also want to echo the recommendation for Modwright LS100. 
I use a pair of Ken-Rad 6SN7 with mine and it’s fantastic. 
Another preamp that I use regularly and highly recommend is a Cary Audio SLP 98, also another 6SN7 based preamp. 
Both has phonos and I bought them used within the price range you’re looking for. 

Cannot go wrong with a properly cared for (maybe upgraded a bit) CJ.