Vintage preamps with stellar phono section.....

Once in a blue moon, you might chance on a Music Reference RM5 for that price. The phono section is very fine for MM cartridges in my experience. Roger Modjeski says it should be ok for cartidges with .5 mv output and more. Having once owned the Adcom you mentioned, I can say I was not very impressed with it. You also occasionally come across Counterpoint and Classe preamps for that price. They also have good phono sections. Another sleeper to keep your eyes out for would be any of the older Muse preamps with phono sections, also excellent.

With some luck on pricing, an older Audible Illusions preamp.

add conrad johnson pf1 and pf2 solid staters to the list. I have seen pf1s in that price range. The pf2 also came in just a line stage only so finding a phono unit may be hard and I am not sure about price used.

I still have a pf1 in use using phono in the lower level. When I got back into vinyl a few years ago it uas paired with a Hagerman step-up (quality unit) for a low output ZYX - .24mv. It was an ear-openinng experience.

TD