Yamaha YBL 620G bass trombone
If you asked me what bass trombone you should buy to start on the instrument, this would be one of my top choices. Easy playing, nice bass trombone sound and it can last you a lifetime even as a pro bass trombone player.
This Yamaha YBL 620G has probably seen very little use and in excellent condition. A tiny bit of lacquer wear here or there, but no dings or scratches. The slide is lightning fast and the valves are excellent.
Price: 3577$ or 2995 EUR