Looking to buy first duplex (House hack) give me your opinion

[Hugo Flores]

Greetings,

I am set on starting my real estate portfolio! I am one year married and I recently applied and got approved for a 200k duplex I am planing to house hack for a few years. The agent said price is negotiable so I am hoping to get the price under 190k. Market is really slow right now in my area so I have a good shot. 

Cost of duplex: $200,000 

Income: $1700 per month. Im calculating between 800-900 a month per unit. (Once both units are rented out)

Expenses per month: (Total $1479)

TAX- $333, Insurance - $100, Vacancy - $68, Repairs - $150, Mortgage - $808 

Cash Flow: $221.  Yearly: $2652

Cash on Cash Return:

2652/14250:  18%

What do you all think? I based this off the loan being 185k which I believe is average and doable for both me and the seller. I will be house hacking for a few years maybe until 20% is paid off so that I dont have to pay mortgage insurance and that would be more cash flow as well. Therefore, cash flow for the first years wont be much or maybe any since we would be occupying one but I am fine with that for now. 

Am i doing the math right and how does this look?