It’s a rather Victorian looking illustration, isn’t it?
Several years ago my wife and I bought a Victorian house built in the 1880s in a small city in the northeast, one that peaked at around that time and hasn’t really made a comeback since. My wife dug up newspaper articles and records on the house, and discovered that it was built at a cost of $3500 (quite a lot in those days). Subsequent sales records for the house showed that it didn’t sell again for a price exceeding that until after World War II.
I think the Professor is trying, and failing, to communicate a concept from the past that is so foreign to us that we can’t possibly understand it: the home as a depreciating asset.