that's actually a myth, mostly propagated by people financially invested in Tesla's failure. the truth is Tesla's vehicles have some of the highest profit margins in the industry. A Model S costs about $30,000 to build according to former executives, and they start at $68k (Most car companies have margins close to 12% per vehicle). the myth comes from the fact that the company currently loses money, but that's only because they are building a ridiculous amount of previously-nonexistent infrastructure like gigafactories, assembly plants, and almost 10,000 supercharger stations (so far).

simply dividing bottom-line costs by number of cars sold is a disingenuous way to determine what a car costs to build, when you are talking about a company that is rapidly expanding and making humongous investments in long-term infrastructure.

sources:
https://seekingalpha.com/article/3968035-tesla-lose-money-every-car-sold
https://www.inverse.com/article/31597-tesla-secret-profit
https://seekingalpha.com/article/3972238-tesla-manages-make-21944-per-car-sold

note that this strategy only works if you have a tremendous amount of capital to burn up front.

definitely not faulting them for that. they have little choice there.