Sawdust follows Me Everywhere
Is it a curve or just smaller straight sections to simulate a curve. Big difference in price.
Who are you?There could easily be 120 hours of shop time.
I would add another 16 hrs for your drawings and layout.
Delivery is another unknown. How large of units can you get in the room? Is there direct access or is all this coming down those stairs?
If you are building on site, I think the labor time is light.