Out-of-state 4-plex

I was perusing the web and came across a 4-plex that may have potential. It's located out-of-state, so I'm treading in new water (on different levels). The list price is $33,900 and all units are currently occupied. I ran a monthly Net Operating Income assessment on the property, and this is what I cam up with:

Income
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Gross Monthly Rent:         $ 770.00
Vacancy Factor:             $  64.17
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Gross Operating Income:     $ 705.83

Expenses
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Management:                 $  69.30
Maintenance:                $  38.50
Utilities:                  $   0.00
Insurance:                  $  14.13
Taxes:                      $  42.38
HOA:                        $   0.00
Other:                      $   7.70
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Total Operating Expenses:   $ 172.01

Net Operating Income:       $ 533.84

If I can get a 30yr 100% loan @8% for the $33,900, I'll have a debt service of $225.54/mo. This will leave me with $308.30/mo pre-tax cashflow. Of course, there are a lot of unknowns yet in this scenario. First, I haven't found a concrete value for the property tax rate where this 4-plex is located. The best I could find online is an "average" of 1.5%. Second, I don't know if there are any repairs necessary or the condition of the property. I also don't know if the landlord is responsible for any/all of the utilities. Lastly, I guessing a 0.5% insurance rate, which may be too low.