Feedback on an opportunity

[Chris J.]

I am considering purchasing 2 duplexes (4 units) owned by the same person. One is 14 years old the other 24 years old and in good shape.  I'm working directly with the owner who built the places and he is asking $300k.  Full rented - $3200/month in total.  Only expenses are lawn and typical maintenance.  B- neighborhood, maybe C+. 

2 questions - Would you buy? Any suggestions on how to negotiate owner financing rather than typical 20% down and 30 year mortgage? Owner has a balance of $100k on a line of credit.

Thanks!