I have had a Rogue Audio RP-7 for about six months and am quite pleased with it. Over the past 18 months I upgraded from an NAD C356BEE used as preamp feeding a McIntosh MC2120 power amp driving my Fyne Audio F702 speakers to an FP-1. That improvement was so very marked and great, I decided to move to the RP-7, which was an incremental but substantial improvement. A Benchmark AHB replaced the McIntosh power amp, and it was a great amp but I wanted to see what a tube amp would do in my system—and hard to audition in my area. So, I opted for the Stereo 100 Dark from Rogue, and I am not disappointed. Great sound stage, excellent tonal qualities of instruments, and three-dimensional sound. But, I must admit the switch from the Benchmark to the Rogue power amp was much less marked than the previous changes/upgrades.
So, I can recommend the RP-7 as a preamp, which as used should fall in your price range. Alternatively, Rogue’s RP-5 is in your price range as new. I may yet have to audition another SS power amp, because, as faulty as the memory can be with audio, the Benchmark SS amp was very close in sound quality to the tube amp I now have. So, there may be something really good in the combo of a tube preamp and solid state power amp. Best wishes in your hunt.