Best tube preamplifier for under $15k

@smodtactical ,
I had the BAT VK5i some years ago, Hovland HP200 , Bel Canto DAC 3.5 , Django passive transformer S&B TX102, Cary slp05,
I also built a couple of preamps that Dennis Had designed and some others.. 
I haven’t heard the prima Luna preamp, it looks descent on paper, but I can’t say. The Freya+ is very good, especially at its price point, but others I tried are more resolving and accurate, IME

I’d have to say Atma-sphere. One for sonic qualities.... and two build quality. Atma-sphere is as good as your going to get. With impeccable Customer Service.

$15K plus tax and shipping. And then you’ll need a proper amp or two. Have at it boys. Here’s what I think is an apt article that appeared in the New Yorker a few years ago.

https://www.newyorker.com/culture/culture-desk/audiophilia-forever-an-expensive-new-years-shopping-guide 

Some people just can’t take it. $15k is a pocket change for hundreds of thousands of people in this country.
If you ask me - $15k for an preamplifier is not enough if you want great sound. Used maybe enough.