WA State Duplex Analysis

[Robert Harpster]

New here and seeking comments on a 1200 sq. ft duplex (2BR/1BA with single garage  each and 600 sq. ft) built in 1946. Asking price $179k. Rents are $600/$575 and under-market by $200 each. Property tax is $100 per month. Tenants have been in over 5 years with no increases. I would like to get for $165k with $30k down and raise rents to $750 each which is market. Cash flow between $700-800 per month. Thoughts?