I recommend the Ayre K-1XE solid state preamp. I used one for 9 years after having used tube preamps (ARC LS-2 and Counterpoint SA-3.1) for many years, and never regretted it a bit. It was an incredibly quiet preamp with a very neutral sound, and it had very good imaging and soundstaging. The used price should be in your ball park.
I have since moved on to the hybrid VTL TL-6.5 Signature, series 1, line stage preamp. (It only has 2 12AU7 tubes, so tube rolling is easy and relatively cheap.) The sound is similar to the Ayre, (i.e. very neutral), but the soundstaging and imaging is even better, and it is every bit as quiet as the Ayre. (I think the VTL has slightly better extension in both the treble and bass regions too, but only slightly, and that might be due to comparing a nearly new preamp to a preamp that was over a decade old.). It is a bit better than the Ayre sonically IMHO, (although my Ayre had the near reference phono boards, so it was probably a better value). The cost is a bit out of your price range, (I paid about $4,200 for mine), but if you can afford it, it will probably keep you happy for a very long time.
My two cents worth.
Good luck in your search!