Help Deal or no deal

[Dee Peterson]

I have a lady selling 3 houses in the same area. The problem I'm having is i can't find any current information on the homes. She has had the properties for 15 years so all the info I'm seeing is incorrect. Is there a place where I can go to see the current value of the homes. I'm working with her realtor and he sent me a page with the addresses and the asking price. All the properties are free and clear and she is willing to do owner finance. He are the terms 

1st house asking price 135k  3bd/2b rents @ 1100 a mo

2nd house is a duplex asking price 180k 3bd/2b rents @ 1500 a mo

3rd house 4bd/2b/1g asking price135k rents @ 1110

She is asking 20% down & 9% interest 

I was wondering if anyone could help as far as what I should do. Oh yea all 3 houses have Sec8 tenants in them the last house i listed will become vacant in 2 mo but the other 2 have long term tenants that she doesn't want me to remove because they have been there so long. Any advice would be appreciated Thanks in advance. Ps she has 7 more properties for sale but only willing to sell 2-3 @ a time due to taxes and I would like to be able to buy them in the near future if this goes well.