Do you have the bill of materials/estimate from the house you're living in? Probably not. It was most likely built by someone you never met (or now wish you hadn't). In the old days, you bought the materials yourself and built your dream home with your own two hands, along with your brothers and sons and friends.
We don't work on our own cars anymore, either. Unless we happen to have a pre-smog clunker.
People had a great advantage in the past --- the art and ability to make and fix their own stuff. May God have pity on us!
Oh, this is a bill of materials for one of my grandfather's houses on Lawrence Drive in San Luis Obispo.