IMO, the biggest problem we face is set-up. A Koetsu on a Durand, if poorly set up, will be bettered by a well set-up rig in your price range. Therefore, choose an arm which can be precisely set up, and will retain its settings. I set up to parallel within 20 minutes of arc (0.001"), azimuth to within 10 minutes of arc.
If you end up using a suspended table, for which an air bearing arm is impractical, consider Pete Riggle (disclaimer: I have not used his arm, but have used some of his accessories, which are well-made and to specification). Otherwise, if an air bearing is feasible, consider a Trans-Fi, which has all the above desiderata. It is also sold factory direct, for $1000 !!!
I used it on a 10K Nottingham Analogue, upgraded several times, and bought another for my DIY air bearing TT. If I were upgrading (a big if) I would only upgrade to a Durand. For what it's worth.
If you end up using a suspended table, for which an air bearing arm is impractical, consider Pete Riggle (disclaimer: I have not used his arm, but have used some of his accessories, which are well-made and to specification). Otherwise, if an air bearing is feasible, consider a Trans-Fi, which has all the above desiderata. It is also sold factory direct, for $1000 !!!
I used it on a 10K Nottingham Analogue, upgraded several times, and bought another for my DIY air bearing TT. If I were upgrading (a big if) I would only upgrade to a Durand. For what it's worth.