All of what you say is true. One thing I want to add though, is that Ph.ds are abundant these days. Because of this, there are certain jobs in industry where you do something similar to research, that require a Ph.d.
On the one hand $700k is more than a lifetime of savings for many. On the other hand I sometimes get surprised by how cheap the most influential politicians in the world are. I guess this sort of thing is regular enough so it adds up?!