Research and development.
I was reading about the design of the Audio Research Reference 330m. The announcements was released about two years ago. When the new owner heard it, he said stop. He hired a team of seven engineers and they spent two years redesigning it and released it recently. Seven engineers for two years... retooling and all that goes with producing a new piece of electronics. Designing the workflow, test points, test routines, manufacturing process.
The speakers in most of the Sonus Faber Amati are custom made and each speaker design achieves better sonics through research and development.
I own Amati Traditional and seen Lilium and other Sonus Faber, they are also the most beautiful made speakers I have ever seen. It takes some craftsmanship to create something this extraordinary.
Why a 20% increase in the price of the Amati. I know nothing for certain but... well, inflation has been going on since the pandemic, throw on tariffs and global uncertainty. I am not surprised.