That is a good point, although I expect the insurance on such a car would be something very special. Imagine the premium on a car worth £840,000!!! Also it is unlikely that like a normal car it actually depreciates. It is more likely to gain in value each year.

It is however true that these cars were made at a huge manufacturing loss because it was more a project to prove it could be done, rather than to return a profit. Unsure how the repair costs would be undertaken in such a car. Probably would be some special agreement directly with the makers to repair it. Plus if you could afford the car, I expect you could afford repairs to it.