The Threshold of a "Good Deal"?

[John Arnold]

Hi, folks. I'm brand new to the Bigger Pockets community and the real estate investing game. I am unbelievably excited that I stumbled across this educational site, and would appreciate any insight to my question. I live in Northern Michigan and I am analyzing properties using the rental property calculator. For context, I have approximately $18k in cash to put toward my first property purchase and I'm looking at houses that are currently listed between $30k-$80K. I've analyzed 3 similar properties and the respective annual Cash Flow / CoC ROI numbers are as follows:

Property 1 - Cash Flow: $3,808 CoC ROI 20%

Property 2 - Cash Flow: $3,890 CoC ROI 30%

Property 3 - Cash Flow: $3,126 CoC ROI 18%

I guess my question is, what numbers threshold should I be looking at when deciding what to bid on? I know there are numerous factors, but I'm trying to avoid "analysis paralysis" by overwhelming myself with all of the angles. These three properties should have no problem retaining tenants, but I'm wondering what numbers I should be focusing on when deciding to take a closer look at making an offer.

Any examples or insight is greatly appreciated!