Some of these CapEx items might have to be addressed as rehab in your initial purchase. https://www.biggerpockets.com/blog/2015-10-13-real-estate-capex-estimate-capital-expenditures

In addition, they always exclude energy and food, which for most families is the LARGE expenditures each month.

Within 3 days, we found a renter.The ResultPurchase price: $195,000Rehab: $21,000Rent: $1,850Cashflow: $499/month (with assumptions baked in, mgmt. fee, expenditure etc)CoCROI: 8.59% (Based on downpayment and rehab cost)CoCROI:28.4% (Excluding downpayment since that was proceeds from 1031)Rental Property Calculator ReportLessons Learned1.

NOI is gross rents minus total expenditures ( not including debt service ) ...

That said, I agree with Nicholas, you are missing vacancy and opex expenditures. 

This would be the first rental that didn't have capital expenditures.

When should you start putting money away for the CAP EX and other expenditures?

You may not know how to handle: tenant relations, maintenance requests, contractors, turnover, lease admin, property managers, "professional" tenants, neighbors, capital expenditures, municipal codes, federal laws, evictions, lawyers, budgets, taxes, etc. and how each one can affect the profits (or eliminate them.)

Cap Ex and Ops Capital Expenditures and OperationsCap ex is the money you need to save to fix roofs, water heaters and furnaces. 

Greetings BP members,Do you think it's prudent to purchase a property with cash, then, subsequently turn around and get a mortgage on the property to recoup your cash expenditure?