Advice needed on the purchase of this Multi-Family

[Lawrence Smith]

Ok, to give a little background info I am considering purchasing  2 unit building in Washington, DC which consist of 2br/1b. These individual units have not seen any type of cosmetic renovation in probably the last 20 years, everything is outdated. Tenants have occupied both of these units for the last 10 years. As that may sound good to some, the owner has not upped the rents to reflect the current rental market and he has not made any of these tenants sign any type of lease. Both units are being rented for $350 a month. Lastly he is selling the property for 180k, if my math is correct I would have to up the rents by at least 53% to receive any type of cash flow. I do plan on leveraging repairs in the negotiation, but my main concern are these tenants that has been here for years with no documented lease. I would need to up rents immediately and if they refuse to pay I think I would be pretty much screwed because there is no lease. Is this a deal I should even pursue give the details surrounding the property ???? PLEASE HELP

                                                                                         P.S. Sorry if I was longwinded