Well, consider this. Robben Ford has been playing a Dumble for a couple of decades at LEAST. He's also used other amps, but he always comes back to the Dumble as his main amp.
He's had guys from Two-Rock, Category 5, and just about every other boutique company out there offer him amps, amps that arguably reproduce the Dumble sound. But Robben still goes back to
the Dumble. There is an elusive and poorly understood detail to Dumble's amp-building ways that, to my ears and hands, has never been quite reproduced with full effect by any clone or facsimile.
Does that make the amps worth $50,000? Not in my opinion. But how far would someone be willing to go to obtain that sound and that feel? That's up to the individual. Some folks can live without it, some can't. If the Marshall sound was as elusive as the Dumble, you can guarantee Marshalls would be going for tens of thousands of dollars too.
I hope my second mortgage goes through in time. 
