I am starting to consider buying a deal for cash now while prices are low and then refinancing or selling once prices go up.

When the cost was super low compared to the potential cash flow.

I don't know if this is a rule of thumb, but it's what I usually do when skimming properties at a high level.   

Ask them when they issue distributions (anything before the 15th of the month is a red flag), do they require reserves, how is maintenance charged, do you see copies of outside contractor bills, do they upcharge materials (PM's have LAR accounts with Lowes and often get 20% off), do they keep all late fees or just the management fee, what other fees do they charge (renewals, inspections, etc), where are tenant security deposits held, how are evictions handled and are you consulted before filing, what screenings do they run, what qualifications do they require from tenants, ask for a couple other owners to visit with for a reference. 

Your unfair advantage is your ability to owner occupy a place and the low down payment loan options that come with it. 

We both have great credit scores (low 800s) we own a property for collateral.  

Impossible to say without actual numbers to weigh but on the surface level, adding an extension seems low ROI. 

Strong employment market and low inventory of rentals ensure demand is always strong.

Quote from @Bonnie Low: Just curious who your clientele are and where you are marketing it?

Im a very vanilla investor, and not well versed in different finance options but it seems like an acceptable, but not ideal, option for getting your foot in the door with low initial funds/experience and very little effort.