Why does any car cost more
Drivetrain, 2.0 ltr turbo or v8 etc etc materials, carbon, leather or usual jdm plastics, body shape is largely irrelevant and its already been developed, moulds will have been made and used.
Guessing you havent driven many modern high performance cars, they have zero issues of parking, speed bumps, too big for the road etc and all are pedestrian safe.
The gtr manages to take on the german marques without issue, why not Toyota, particularly if it looked like the Ft1, thats the target market.
Anyway, I couldnt afford one but wouldnt be spending my 60 or 70k if i had it looking like your link