Just the manufacturing of an all metal and glass lens is a very expensive proposition today. A Sonnar is 6 elements of different refractive indices glass, all aligned and cemented. It's coated, and mounted in a precision brass fixture. As an example there is a US manufacturer trying to replicate an 1800s Petzval portrait lens for Large Format. They discovered they couldn't make the barrel in traditional brass for the target price, so had to use aluminum. (like LOMO did on their Petzval I believe). That lens is going to cost $1000.
Its also the economy of scale. Fuji can make 20,000 X-mount 35/1.4 lenses and their prices have gone down from about $700 when first out, to about $350 now. The new J-3 will not attract that many buyers, it's a niche lens, so it's expensive. But it will go down in price over time. Just wait a year if you want the price more in line with Voigtlander 50mm lenses.