It's difficult to calculate the exactly cost.
For some parts I had to pay initial cost (like the PCB)
on other parts was a minimum (I have 100ft ribbon cable at home)
or other parts didn't achieve my standard.
I have made one for me and sold one kit to a good friend.
(It's a "small" version with a silver front-panel and blue lenses)
With the spare parts I can build up 3 housings.
If I can sell the housings it helps me to reduce the cost
and you will get an excellent housing for a fair price.
the guiding price is for the "power" version 400€
and for the "small" version 300€
Let me know if there is any demand?
Andy