"Hand-built 7.0-liter V12 engine with a chassis made of aluminum and carbon fiber."
Handmade in the UK is definitely not normally expensive, let alone getting an engine as complex as a 7.0L V12. The price of a carbon fiber rear wing is corrupt as hell, so you can imagine how much it costs to get a piece of floor pan.
"Matching a 6-speed manual transmission mounted in the rear center"
Seems to be a front engine rear wheel drive, transmission is placed in the back to balance the center of gravity of the car, this layout is generally expensive. For example, BMW, Mercedes, Lotus, and other brands that one associates with expensive at first thought.
"The ONE-77 will be a 2+2 structure, including a carbon fiber chassis, hand-built aluminum body, and an estimated net weight of around 1,500 kilograms."
Keywords: handmade, aluminum, carbon fiber And exceptionally light.