When Sandy Munro first took apart the model 3 engine, he noticed that the magnets consisted of smaller magnets glued together. It took him months to figure out the reason behind this: Tesla found a way to increase performance of cheaper magnets to match better, more expensive ones.

This one change saved Tesla a ton of money. Ford, on the other hand buys their motors from an electric engine company, thus eating away at their profits.

This sort of thinking is what has allowed tesla to achieve a 30% + profit margins per car (and going up every year).