Michigan investor looking to buy tenant occupied rental

[Nathan Hall]

Hi.  I'be been talking with a seller that has two homes he wants to get unloaded.  He's tired of the landlord game and wants out. One of the properties is occupied with a tenant.  She's been there for 15 years, has section 8 subsidy so the rent is always paid on time. The seller doesn't want to "spook" her,  so I haven't seen the inside yet.  If he's on the up and up,  and I'll find out here this week,  the house is in decent condition with no issues other than it being old and occupied for 15 years.  The rent is at market for the area.  It's a 2bd 1bath house, 900 sq. ft. 10 year old roof.  Newer furnace and water heater.  The recent sold comps average out at $35k. He's asking 20k, but I've got him considering 11k. I won't move on it of course, until I see the inside.  

What are your recommendations regarding this long term tenant?  She's been a good tenant since the beginning.  The lease is month to month now. If the house is decent condition, does this sound like a good deal? How would you go about financing this deal if you were cash strapped like me? If everything works out,  if hate to miss out on having my first rental with a good tenant already in place.