It will be a small BLDC servo motor driving anti-backlash geartrain I suspect.
The gears will be smothered in silicone grease. Nothing about it will be cheap.
That, and they are selling it to photographers - some of whom likely think nothing of spending $2k+ USD on a gear motor.
Honestly - even if that that thing had every bit of tech you mention, and more (nylon herringbone gears, etc) - it still shouldn't cost that much; it only costs that much because people (some with more money than sense, I suspect) are willing to pay that much. Although it is meant for a particular photographic purpose; maybe it does have to be super-ultra smooth and quiet for that purpose - I'm not a photographer, so I don't really know; I just suspect it to be over-priced (any photographers care to educate me on the subject?)...
That said - quality gear motors with extremely quiet drive characteristics won't be cheap; I would expect to spend in the hundreds for those - not the thousands (at least for something that isn't designed and marketed for a niche product purpose, like this lens motor).