Socrates (or Xenophon, anyway) also talks about the property business in Xenophon's Estate Manager section 20 (that is, section XX). His character, Isomachus, describes to Socrates how it is advantageous to buy up undeveloped or unworked land, develop it, then sell it at a profit. That was written around 380BC. Property has obviously been good business for a long time!

Of course, it also requires luck, good market conditions, and, above all, application (i.e., effort or self-discipline: a common Socratic theme).

I think one problem I have is that I keep looking for work I can do that will allow me to remain lazy. Hmm... Might have to abandon that particular project. Until I'm rich.