How do I know a good cash flow return of I pay a rental in cash

[Santos Vargas]

I'm looking into buying a property in Pennsylvania , Tannersville , in cash . $250,000 multiplex 6 bedrooms 2 baths , 2 kitchens , two level home ,property tax of $5,885 in 2019 , I want to take the second floor and rent the 1 floor . There 1 electric meter I would have covered into 2 meter a cost of $2,000.00 , well water , and septic tank set , heating electric / oil "I would pay" . 3bedroom 1 bath n kitchen per floor ., I have been inform that going rate of rental is $1,000 -$1,200. After my guesstimate I'm looking at a cash flow of about $300. After expenses and taxes monthly of 490$ . I know I don't fully have all the numbers in expenses but regardless does anyone believe this would be a worth deal for a $300.00 or even less cash flow monthly ? Thanks guys . Newbie