About $4 at our local scrap yard LOL....
Harley used to set their engine blocks outdoor in the weather for 2 years to 'season' them as standard practice; stress relieving them and allowed them to 'relax' to their final shape after casting but before machininng. I remember driving by the yard outside their factory near Milwaukee many years ago and seeing that... but they did not bury them. Maybe only cast iron gets buried LOL