I own the SLP-98P. Before that, I had a Cary SLI-80 integrated amp. Both have the characteristic Cary house sound, warm and sweet with musicality up the wazoo. I had a Musical Fidelity A300 integrated amp before I got into Cary gear. The MF is much more forward with the soundstaging, which results in a harsh, fatiguing sound for my ears, JMO.
The SLP-98 is considered the best current production Cary preamp, but Cary just came out with the SLP-05, which adds two more 6SN7 output tubes and a MM/MC phono stage with switchable impedance settings, among other things. I haven't heard anything about the SLP-05 yet, but it seems very promising.
The SLP-88 can be had for your price range, but it only has 2 12AU7 tubes. I imagine the sound would not be quite the same as the SLP-98 or the SLI-80, which have different tube sets.
A used 50A, as mentioned above, or the 50B, would probably be good options at your price range, but this is only based on what I have read. I would also look into AES.
You don't mention the amp that would be paired with the preamp. When I auditioned the SLP-98P, it was first hooked up to a BAT VK-55 amp. The imaging was shifted way to the left, for some reason. The sound was also cold and sterile, to my ears anyways. Then I had it hooked up to the Cary V12R, and the imaging was perfect and the sound was magical.
If you are also getting an amp, consider the SLI-80 integrated amp (if your speakers match it). You can get a used one for about $1800. You can try it out to get a good idea of the Cary sound. If you don't like it, you can sell it at or near the price that you purchased it for. I went this route, and ended up upgrading to the SLP-98P and V12R.
One last note - Kevin Deal at Upscale Audio is an excellent source of advice for all things tube. Try him, or ask your local dealer, if you have one, for advice.