Seller financing deal

[Taylor K.]

Hello everyone, 

I have recently come across a package of properties for sale by owner. There is a 4 unit and 2 duplexes. The asking price is $120,000. The gross rent is $4200. He is wanting to owner finance them. He wants 15k down, and the rest of the balance financed at 3% ammoritized over 7 years. Which comes out to ~$1600 a month in principle and interest payment which leaves almost zero cashflow. I am thinking about offering 15k down ammoritized over 20 years with a balloon at 5 years. This way he can get his full money back sooner and have great cashflow. What do you guys think?