Your main costs will be Property Tax, Property Insurance, Maintenance (small repairs, landscaping, pest control, etc), Capital Expenditures Reserve aka Cap Ex (money set aside for roof, HVAC, Flooring, etc), Vacancy, Property Management, and then any debt service you have on the property.

I would also have 7% or more of capital expenditures like a roof, paint, new HVAC, repaving the parking lot, upgrading facilities, etc depending on the amount of differed maintenance from the prior owner.

A lot of these homes are older and your on paper 2-3% rule can easily disintegrate with capital expenditure and/or eviction/turnover. 

You can make a profit now and the rents don't provide enough of a buffer for future capital expenditures.

The blog suggested putting aside $200 for capital expenditures, which I've been doing when running the numbers.

How do I know things like the cost of water and sewer, loan points, ARV (without an agent to pull comps), Capital Expenditures, or any other number of items without fully engaging the seller? 

Like you said, it will require so much capital expenditure and patience.

@Nancy B.The DMSH is less an expensing election and more a book conformity election.There's a concept involved in the DMSH and other areas of the capital expenditure code section and regs called "units of property".You don't examine each line item on a receipt, you examine "units of property".Buildings are called out under the units of property regs as having special treatment. 

We have a $1M Capital Expenditure (CapEx) budget that we are using to improve the property.

You also have to take into account the long term capital expenditures.