What is the best tube pre for $350 used? HF detail

Anyone can get a great sounding tube preamp for $6000, if you have the money to blow, have the ears to tell a difference, and care enough to spend that much. Same thing with $3000 or $1000. Let's lower the bar as far as it will go and see what gets under it. I am looking for a tube preamp with the best soundstage and high/mid frequency detail possible for the $300-350 price range. A little bright is OK. Upgrading the tubes/mods later is OK. In that price range I have found Audioresearch, LA audio, Amc, Conrad Johnson, YA audio(maybe). Golden tube is out because I can't afford to throw it away when it inevitably breaks. Out of those or any others, what do you think can yield the best soundstage and upper freq detail?

Thanks!