If you do things properly, you shouldn't have capital expenditures for a while.

That is, how much money is left over each month after you pay your mortgage, taxes, insurance, repairs, capital expenditures, and management (if you have a property manager)

Now while finance advisors like Dave Ramsey would tell me to pay off my debt, stop frivolous expenditures, and save money, my total debt combined with my student loan is under 10 k, (aside from my house and car) I have been trying to lower my debt for student loans and credit paying $500/mo, and frankly, I just don't have ANY extra money ( not even to save $250/mo thanks to Sallie Mae).

Monthly cash flow of $350/month, obviously a portion of that will be used for repairs, maintenance, and capital expenditures.

This is to account for vacancy, repairs, management (even though i self manage i likely will not in later years) and capitol expenditures.

@David Nacco - first make sure to account for the following expenses in your calculations:1) Mortgage2) Mortgage insurance (PMI or MIP) or FHA Risk base3) Property Taxes4) City Taxes5) HOA (Home Owner’s Association) Dues and Fees and Assessments6) Insurance a) Property Hazard Insurance (0.3-0.45%) b) Flood Insurance c) Earthquake Insurance d) Umbrella Insurance7) Vacancy Rate (usually 8% - the equivalent to one month a year, or 5-6% if multifamily and/or if experienced, if not use 8%)8) Utilities (you’ll have these if your tenant is not covering them and/or during vacancy) a) Water § Sewer § Garbage b) Electricity c) Natural Gas d) Propane9) General Maintenance (usually 5%) a) Upkeep § Landscaping b) Snow removal c) Repairs d) New Appliances e) Make ready10) Capital Expenditures (usually 5%, higher is the property is old and obsolete, less if fully rehabbed and all mechanicals and roof are new)11) Property Management (8%, even if you self manage, your time still has value and there might be a time when you'll want to be completely hands off or you'll not be able to do it, vacation, retirement, etc.), including...

Capital expenditures: example floors 1000 sf @ $6 sf = $6000 / 8 year life span /12 months = $62 per month.

I try to make my houses as tenant proof as possible and knock out all of the things that could end up being major expenditures down the line.

It's not a red flag at all; it happens all the time - just keep a record of all expenditures prior to placing the property in service. 

What is the historic vacancy for the area, what are average rents for the area, what capital expenditures have been done to the property, has the current owner bumped rents or done anything to increase cash flow?