$550, $700, $800 depending on the model (plus shipping and import). 4 week build time according to website. I'd give this a read if you're interested: https://www.talkbass.com/threads/arkham-zephyr-tube-bass-preamp.1141059/
I liked the idea of the JHS when I first saw it, but I've been reading more bad reports about lack of headroom on them than anything good...