You might remember that George Caswell had a nice .250-3000 and a .404 Jeffery Type A at the same time back around 2017. He told me that he had sold the .250 for 14k. I don’t know about the .404 but it didn’t last long.
George told me another story recently about acting as an intermediary on a prewar .416 Rigby that went for 50k sight unseen. It was apparently nearly new.
There are some serious Mauser collectors out there and they know the good stuff!