My take on this is the following:
One, anyone who can afford the DarTZeel products has money, and lots of it. (And that is a good thing in my book. And yes, I wish I had more of it too!) People who have lots of money can afford to buy and sell equipment until they get (in their mind) the perfect sound. Or, they can afford to think of the buying and selling (and the auditioning of equipment) as their hobby. Hence one of the reasons why people who can afford to buy DarTZeel equipment can also afford to take the monetary loss when selling them.
Two, the DarTZeel amp (I've never heard the preamp, so I can't comment on that) is a wonderful amp. It has some of the best imaging and soundstaging characteristics that I've ever heard. (The mid-range is fantastic, especially for a solid state amp, and the treble is nearly as good.) However, it is a stereo amp, (rather than being a monoblock design), and it has somewhat limited power (@ 100 wpc), and therefore, it can run out of power driving inefficient speakers. Therefore people have tried it with the hope that it would work for them, and when they found that it didn't quite work, they sold it.
I would not read too much into the selling of even the best equipment. There are always people with lots of money around who like to experiment. Sometimes they buy the different units just to prove to themselves that what they already own is better than anything else out there.
My two cents worth anyway.
One, anyone who can afford the DarTZeel products has money, and lots of it. (And that is a good thing in my book. And yes, I wish I had more of it too!) People who have lots of money can afford to buy and sell equipment until they get (in their mind) the perfect sound. Or, they can afford to think of the buying and selling (and the auditioning of equipment) as their hobby. Hence one of the reasons why people who can afford to buy DarTZeel equipment can also afford to take the monetary loss when selling them.
Two, the DarTZeel amp (I've never heard the preamp, so I can't comment on that) is a wonderful amp. It has some of the best imaging and soundstaging characteristics that I've ever heard. (The mid-range is fantastic, especially for a solid state amp, and the treble is nearly as good.) However, it is a stereo amp, (rather than being a monoblock design), and it has somewhat limited power (@ 100 wpc), and therefore, it can run out of power driving inefficient speakers. Therefore people have tried it with the hope that it would work for them, and when they found that it didn't quite work, they sold it.
I would not read too much into the selling of even the best equipment. There are always people with lots of money around who like to experiment. Sometimes they buy the different units just to prove to themselves that what they already own is better than anything else out there.
My two cents worth anyway.