People who come here illegally are often good hardworking people looking for a chance it's the people bringing them here you have to worry about elements of organized crime and generally scumbags willing to exploit the weaknesses of our great country....If they pay rent your golden if they don't they will probably be easier to evict since there not likely to go through a legal process and will probably just leave quietly but good luck 

Also, maybe I could advertise that my rentals are more environmentally friendly in addition to more cost saving. 

But $ / Sq foot to me is not enough as I like to look at the class of neighborhood, property type (duplex vs apartment) all of the elements that can impact rental rates.

Modern environmental regulations either discourage or ban the use of cesspools, and instead connections to municipal sewage systems or septic tanks are encouraged or required.

They can sell you an element for $20-$45 and will probably show you how to replace it yourself.  

That would certainly add a very costly/unpredictable element to my plan.

@Anita Parsa the only thing you need to be afraid of is going at it with no education and no team supporting you.I have found that these two elements mitigate the fear AND risk factors.

What I mean is - if each element is on its mark, there isn't a reason the property shouldn't sell.  

Ended up they had 2 bad dryers, one with a dead thermostat one with a dead heating element. 

The problem with them is the limited number of apartments available compared to those who need them, and the violent criminal element using these places as homes between prison sentences making them dangerous to other who live there.So there are solutions, just not perfect solutions.Good Luck!