Another major factor is...what do you want to invest in? 

Gotcha, so really a big factor is having a massive amount of equity to protect. thank you for your response 

Please please please do not go to a tax prep factory like H&R Block - I see so many mistakes from "qualified tax professionals" on clients' returns who switch over from H&R Block.

And, by risk factor, I mean actually losing the home(s).For me, I could see someone doing 2 or 3 of those high appreciation houses and then the rest in more stable areas where they can get a balance of cash flow and moderate appreciation.

For those who don't know and don't have what it takes, it will likely be a failure.IMO, one huge factor is the investor/landlord must be comfortable with the intended customer base. 

I suppose then the move from the factory to the initial plot of land counts as the first move.

Modular HomesManufactured homes are often more affordable than modular homes because they are built in a factory and transported to your land.

Only $3k-$5k from factory to backyard. 

The Tesla factory and other tech companies moving to the area is a big plus.

After 9/11, congress (idiots) was very concerned about Al Qaeda buying residential real estate, but congress wasn't really worried about them buying apartment buildings or shopping centers or aircraft part factories (like I said, idiots).