Duplex Owner Financing BAD Tenants

[Dean Klein]

I am asking for some tips or advice, I am going to take a 2nd look at a duplex in my town that the owner is in his 70s and has 100+ properties and wants to sell some before he dies. The owner is willing to carry a note for 7 years at 4% with a 10k down payment, and the purchase price of $75k. It is 1 2/1 and 1 3/1 apartments renting for a total of $1400 a month, and my payments to him would be amort over 30 years but the tenants currently there are a son in the upper and his mother in the lower and they are filthy, it seems like they trash it just so I don't want to buy it, what kind of things should I include in my offer to purchase such as having both tenants out before I take possession, they fight the landlord on letting me come view the inside and they say they NEED to be there when I go there, and I was planning on having an inspection and bringing in an HVAC, electrician, and plumber to tell me any issues if any, this is a 100+ year old duplex. Thank you!