i have read some posts that says that REF5 is made more simply than ref3. Fewer parts, easier solutions etc and that it should cost less than ref3 even if it sounds better and that to the benefit of the audio world.
A skilled technician I know who has looked inside both ref5 and ref3 say the same.
So why not 8000USD for ref5 insted of 12.000USD.
On the other hand a ARC local agent says it has new technology that cost more to develop and produce.