Or any dog, no matter breed or size, that jumps at me when I meet them.

There's no one-size-fits-all methodology.

Hello, managing these types of small to medium size projects or really any repair is incredibly difficult when trying to self manage remotely.

The gross will depend on the size of the property, the net will depend on how you manage it. 

On the one hand you could buy a turn key duplex or tri plex in Cleveland that cash flows decently, or on the other side of the spectrum you could MOVE to Cleveland, house hack a distressed 4 plex using FHA with 3.5% down (~7k), rehab this (~20k), then refinance out in a year using a local credit union to recover all of your money, all while BRRRR'ing another single fam house, then repeating the following year, to accumulate 15-20 units in a few short years, with the plan being to expand into mid sized multi fam vs syndication after that.

I try to keep the comps within 10% but if there's a difference of a hundred sq. feet or so I'm not sure what degree of adjustment to make although I'm sure it depends on the size. 

Nah, I'll pass, if I am really desperate I can offer the project for 13% less than what I am willing to pay, but this size chunk makes it unattractive to investors and good contractors.

@Joshua McMillion mentioned one way-ROI.When it comes to real estate, returns come in different shapes and sizes.

How are the lot sizes? 

Are there other methods like a fixed dollar amount based on the size of the house, age of the house, etc that you use instead of a percentage of rent?