I doubt that replacing painted regular steel with fancy stainless steel is going to be cheap. Paint is expensive, but so is stainless steel. I also can't imagine the "origami" technique to be cheaper than stamping, the reason they suggested that is because their fancy stainless steel can't be stamped. And in the end, Tesla couldn't even do it, so they glued the parts on...

I don't know any item where the unpainted stainless steel version is cheaper than the painted steel version, thinking about kitchen appliances for instance. For cars, the most famous car with a stainless steel body is the DeLorean DMC-12, which was notoriously expensive, even without the time circuits.