I was looking at a 4-plex near my home and saw that there were probably 20 identical buildings on the same street, all looked identical except for paint, etc.

A more precise way of explaining what I'm saying is that you should always invest cash in whatever investment you can find that yields the highest returns.Paying cash towards your mortgage is financially identical to investing in a zero-risk investment that has an annualized ROI equal to your mortgage rate.

Recently in my area a broker got nailed for mail fraud since he used the mail in connection with his wheeler dealer RE practices.

Well, that first matter is just mortgage fraud if never moved in.Look at the other loan for a pre-payment penalty, if there is you may need to deal with it, if not you don't.

He advocates tax fraud telling people to deduct vacations and spa memberships.

It's a home almost identical to the one I'm looking at which is also in the same neighborhood.

Generally being on the cutting edge of fraud games down here, scumbags haven't tried to in these situations, they just rent them out.

Our spam system is pretty sensitive, and it's usually from sending posts that are too similar (like, identical) Hope that helps! 

That would be fraud.

I'm simply saying garbage in garbage out.I'd say what is being overlooked is the very basic fact that all real estate is unique, no two parcels on earth are the same, they may be similar, but not identical.