@Nick Vehr That seems fine - I'd consider pushing it to 20% if you can identify any concrete expenditures (water heater, furnace, roof, etc.) or if it's an older building, but otherwise that should be a fine estimate from what I can tell.

I never tolerate that in tenants and teach mine that their most important priority in life should always be maintaining a roof over their head.

Make sure the plumbing, roof, electrical & HVAC are sound and you should be fine.  

I propose that the reserve goal is $5000; which is enough to cover a roof.

Especially since it can become a lien on the home.For a duplex in non-drought areas it's not so much about the water as it is these steep fixed fees for garbage and sewer.

Avg rent is $900 or lower, deal prices ranges from $39-$79Krehab around $50-$100K- ELECTIC,ROOF, PLUMBING would need re done- Knob-Tube Stuff.Comps $120-$140 if your lucky cause no one would want to OWN here do to the neighborhood. 

Also, this house needs a new roof, so if anyone could recommend someone for that as well that would be amazing. 

Even if you don'st spend it, you'll probably need $15-20K in reserves for one major issue or a roof replacement depending on it's age.

This home was bought by the seller, flipped and remodeled with new roof, completely redone and new kitchen with appliances, new HVAC, furnace, water heater, etc.

I have never rehabbed a house so I don't necessarily know what a contractor would want to do to it, other than obvious stuff like a new roof and paint or replacing old cabinets.