I have bought properties for under $30k as late as June of this year, Single Family Residence (SFR), and fixed it up for another $15k ($45k total) and it is producing over a $1,000 in rent now per month.

Rentals will actually produce double rent and everything will be fine" ¯\_(ツ)_/¯

I was curious, from an appraisal standpoint, what people have seen when adding additional income producing units to single family homes. 

I'd suggest a blended approach maybe to further shore up your security.First take a look at those properties and identify the one (not your residences) that either have higher debt or are under producing what you think you could get with a different structure. 

In other words they give you a $100 credit towards your job if you paid them that much to produce the bid. 

My goal is to have cash producing single family and multi-family homes and to have passive income exceed my expenses ala "Rich Dad, Poor Dad".

There is a lot of development around and we definitely are producing a unit much higher than the typical in our area, but I expect others to follow suit soon.

Two things generally happen, they will all of a sudden produce proof of income, or they want to cancel the deal because it's not what they say it is.

Put another way, I am less concerned with cash flow in the super near term but rather looking to make investments into solid rentals that will produce sufficient cash in 5 years.

This produces 10% cash on cash, which is on the low end, but you have no management costs in the expenses.