Crate engines sell for between $3000 and $12000 for cars. Transmissions $2000 to $5000. (Prices from the first source I found, a reasonable sample range but I suspect you can find things outside the range) In stock and ready to pick-up today at a warehouse near you.

They are expensive, but rarely more than the car is new.

And in the account I read they had simply run over some unknown road debris on a highway. Something most people could imagine happening to them.