please help me evaluate this deal

[Marci Stein]

It's a duplex in upstate NY, 2 three bedrooms apt, section 8 tenants, 

both have been there for 5 years paying $800 a month, plus all utilities (except water).

yearly income $19,500.

yearly expenses (taxes, water, insurance) $7,4000.

purchase price 90,000 , 20% down with OWNER FINANCE @5% interest.

house has 2 new furnaces,in very good condition overall.

i think it's  a good investment, but would love to know what others make of this---thanks!