Good Seller Finance Terms

[Mike McCarthy]

I'm considering purchasing a pair of duplexes from an older gentleman. He's been renting these properties for 25-30 years and is looking to be done with them. I'm considering a seller-finance offer to help with closing speed and not go through the mortgage process. (though I do have good credit score, decent DTI - but mortgages are a pain these days).

What would be a reasonable starting point for an offer regarding financing?  Price would be around $450K.  If I was getting a conventional mortgage, I'd be putting $112K down (25%), and pay 5.75-6% for a 30yr.

What should I offer him to be both reasonable and competitive?