Don't be cheap about mailing man.

Cheap rentals require cheap repairs.One interesting thing I just observed is that over a 20 year period on a sfr my monthly cost for maintenance, cleaning, repairs and capex were $171 pm while a duplex during the same time had a monthly of $195; only $24 higher for the extra unit.The big thing though is that the sfr has appreciated at twice the rate as the duplex.

That's as cheap as I know @Edward Orlando 

If you buy something cheap enough that there is a big margin of safety, you might not hit homeruns, but you will consistently hit singles and not endanger your capital. 

After a while you start to know what to look for and may be able to find the big issues yourself.I have found that Baltimore-especially the city, has plenty of cheap 100+ year houses with serious structural, foundational, etc. issues that I, like you, would not have the stomach to want to deal with if they gave it to me for free!

I got lucky on being knowledgeable when prices were still cheap.

Look - I know investors are enticed by the word "cheap" (I'm an investor too), but "cheap" and "contractor" should never be used in the same sentence.  

It simply feels like a cheap slap together house that someone is trying to make a quick buck off of.  

As their is only baseboard heat and window air now.  3-4k per apt is a pretty cheap install.  

If you have cheap leverage and the ability to earn a higher ROI on the money by using it to fund the next venture I would use it towards the next venture & keep the loans open.