Is there a place on the internet whereby one can find the LEGITIMACY
of "get rich" seminars such as J.T. Banks on investing in probated
real estate, by buying low and selling high?

Seminars are not the problem.  You can tell people almost anything you want.
It is a question of the validity of what the speakers are pushing,
which may be very legal, but not nearly as assured "get rich quick
scheme" as it is presented.
"Buying low and selling high" is a universal maxim, but --

If they really had a perfect scheme for doing what they are telling
people who pay to hear them, they would be keeping the secret to
themselves and using it.

But they  -and others like them with different "get rich" theories - 
are earning their money selling seminars and probably their books.

Think about it.  Maybe a researcher can provide an answer supported by references.