CapEx as I understand it is Capital Expenditure. 

A duplex in a good area should give you good tenants and not too many headaches.One percentage I might question is the 10% for maintenance and capital expenditures.

You should have some type of reserve study to analyze future capital expenditures.

Learn about operating costs, vacancy factors, and capital expenditures.

Capital expenditures have to be depreciated over multiple years.

As a frame of reference the realtor I dealt with three years ago to buy my personal residence answered his phone or text the majority of the time right away or would return your call within the hour; that is what I have come to expect as the norm until now.The snot nosed kid in the backseat comment was way out of line considering the lack of information the poster had beforehand; on average I contact my agent about once a week to exchange information, not cry about not having showings/buyers.I expected going in that this house would take longer to sell, I didn't go overboard with updates or expenditures, and I have it currently listed about 10K above my break even point.  

You should be budgeting for maintenance and capital expenditures.

Even if it takes 10 hours, an extra $1350 in your pocket is huge.The numbers on this place will tell the story:Rent $1350Mortages, Interest, Taxes, Insurance $1050$300 left for everything else$150 budgeted for Capital Expenditures (new roof, new water heater, etc) and maintenance  (minor plumbing repair, fixing a busted screen door, etc) - $150 leftVacancy - $108/month - $42 leftThat is what you get to put in your pocket at the end of each month.  

Below are my numbers (I ran the numbers as if I am financing the 10k through HUD at a 30 term, although I'm just losing potential interest 2-4%) Purchase Price $10,000.00       Home Value     $47,500.00       Interest Rate     3.5% Down Payment 6.00% of the purchase price $600.00 Amount Financed $9,750.00       Income       Rent     $1,000.00 Other Income     0 Capital Appreciation Rate -1.60% per year of home value $46,740.00 Total Income $1,000.00       Expenses       Mortgage 30 year term $27.08 Taxes 1.05% of value of home $41.56 Insurance     $100.00 Flood Insurance       Repairs 10% of the mortgage $100.00 Vacancy 10% of the monthly rent $100.00 Capital Expenditures 10% of the monthly rent $100.00 Water   Tenant pays $0.00 Sewer   Tenant pays $0.00 Garbage   Tenant pays $0.00 Gas   Tenant pays $0.00 Electricity   Tenant pays $0.00 HOA Fees   Flat Lawn Care     $25.00 Property Management     $110.00 Total Expenses $603.65       Cash Flow $396.35 Cash on Cash Return on Investment 66.06% Annual NOI     $4,756.25 Cap Rate     792.71%Am I missing something critical?

So my capital expenditures should be very low, if any, depending on the amount of time I keep the house.