Instead, since it leaves out the financing (1 huge variable in your ROI) it is used primarily to make quick comparisons between properties. 

If purchasing a two-family, what type (raised ranch, side x side split etc.) would be most beneficial given my current housing costs in relation to the purchase price per unit in comparison with four units?

Does anyone know if a mixed use 7 unit building would be appraised with the income approach or by sales comparison.

I had a $1350 month rental and bought a $1100 refrigerator replacement, in comparison, but I personally would also be very reluctant to replace @10k refrigerator esp. for those particular tenants.

After doing market comparisons, I believe I can charge anywhere between $1,500 at the lowest and $1,800 at the highest for rent. 

Once you have pictures of the comparison no one can deny when the damage took place.

Is that through a comparison of what the market is around and what the comps are like?

The best approach is to leave these costs out of the comparison calculations.

In comparison, you may buy a rental property with $1100 payment, but you are collecting $1700.

I wrote about my experience and included a comparison chart for different LVP brands here.Good luck!