You need to look at 3 things.Capital Expenditures..

He said that one of the main issues is that the buyer didn't have the financial means to personally support the property, meaning he couldn't afford any unforeseen capital expenditures or if there was a high vacancy rate that this property would bankrupt him.

Capital expenditures are minimal with the the recent reno and a property manager told me they'd be easy to rent and may be able to slightly increase them by a few bucks every month. 

This would include accruing approx 15% from gross rents for Capital expenditures and repairs/vacancies.

Gather estimates for capital expenditures.6 Show vacant houses to prospective tenants.7.

I would love to get this deal done and with me managing the property I would cash flow around $250 a month (taking our 5% vacancy, 5% repair, 5% capital expenditures) and would't have to put down any cash minus closing costs. 

I figure maybe up to $1050-$1100 rent, tenant paying less right now but pays on time, it still enough to have some cash flow while paying mortgage, taxes, ins and setting aside for vacancy, cap expenditures, and repairs.

I am going to hold onto the property knowing I am going to have some capital expenditures coming soon and continue renting it.

Your repairs will be out of pocket and can be counted as either expenses or treated as capital expenditures adding to your basis (talk to CPA who knows rental real estate).  

I ran the BP Rental Calculator with the assumptions:Vacancy: 10%Repairs & Maintenance: 10%Capital Expenditures: 10%Property Management Fee: 10%Annual Income / PV / Expenses Growth: 0%Sales Expenses: 0% Having never bought a unit, I could definitely use any insights into the assumptions for this area.