Analysis Help, Please

[Ryan Wamsat]

I am considering purchasing my first out-of-state rental property, which is an off-market deal.  I'm rather nervous about this one, as it'd be the first one that I haven't occupied before turning into a rental.  Please help me out with the deal analysis.  Are there any pitfalls that I'm not considering?  

This duplex is in Massachusetts, and it is an older home; built in 1912.  The first unit is a 3/1.  The second unit is a multi-floor 2/1.  There is a long-term tenant in the 3/1, paying $1,000/mo, which seems slightly under market value.  A quick look around the Internet suggests that the second unit would rent for $875/mo.  From the pictures, the house doesn't appear to need much work, so the repair budget is low.  If I do move forward with this, I would fly out there and see the property first-hand before committing.

• Purchase Price: $115,000
• Closing Cost:  $2,500
• Est. Repair: $5,000
• Down Payment: $23,000 (20%)
• Repairs: $5,000

Expenses

• Monthly Payment: $459.34
• Vacancy: $92.50 (5%)
• Repairs: $185 (10%)
• CapEx: $185 (10%)
• Prop Mgmt: $185 (10%)
• Tax: $311.46 (3.25%)
• Ins: $143.75 (1.5%)

• All-In Costs: $30,500
• Cash Flow: $304/mo
• Cash-on-Cash: 11.96%
• ROI: 8.36 years

If there is anything I've omitted, please let me know and I'll find the answers. 

I appreciate everyone's help!

Ryan