Invest:to put (money) to use, by purchase or expenditure, in something offering potential profitable returns, as interest,income, or appreciation in value.Believe me, I do recognize the desire to acquire things that I am passionate about.

Make sure you don't have any large expenditures that are not easily explained before you get your loan.

@Micheal Rieves,You are forgetting:Maintenance @ 5% ($4,551)Property Management @ 10% ($9,102)Capital Expenditures @ 5% (not 10% because you stated some of the important stuff is newer like the roof, windows & siding) ($4,551)So your cashflow of $24,000 is actually $6,000. 

I'm sure there will be capital expenditures and vacancies and other surprises that eat into that but for the sake of argument, let's say $400 a month cash flow is attainable, which it definitely is.

But here are the basics to account for.Property taxes, Insurance, Capital expenditures, Simple repairs and maintenance, and Vacancies in the other units.

Expenses being: Mortgage, Property Management, Insurance, Property Taxes, Repair Ratio, Vacancy Ratio, and Capital Expenditure.

30k could get you a property, but you have to consider capital expenditures (HVAC goes out, roof replacement).

Depending on how long you want to hold the house, setting aside money for capital expenditures (roof, HVAC, water heater, etc) will come in handy when you need it.Hope that helps!

Estimated Expenses (annual)Real Estate Taxes (estimated 4% purchase price)Property Insurance (estimate 0.75% purchase price)Property Management (11% rental income) Repairs & Maintenance (10% rental income) Utilities ($75 water / month / unit + $25 trash)Lawn care (estimated $100 / month x 6 months)Snow plow small driveway / parking  (estimate $100 / month x 3 months) Capital expenditures (10% potential rental income)

It is a one-time expenditure.