FSBO Quadplex; ask for owner financing

[Gallagher Wilson]

First post on BP, love the content.  Been pouring over this for a few weeks and love the amount of advice and encouragement that floats around here!  

My wife and I are closing on our first SFH buy/hold in Shoreline, WA in a few weeks. In the meantime, I found a quadplex a few miles north. Owner has been in it for 20+ years (likely has paid off, or mostly, I haven't verified) and is interested in selling. We've dialogged via email the last 6 weeks, and he's getting closer to ready to sell. Because of our current debt/income ratio, and conversing with my lender, getting a loan on this is a stretch for me at the moment. The cash flow is good and there's room for improvements as well. If you were/are a seller, what is the motivation to owner finance? Tax benefits in not taking buyout in lump sum (assuming he wasn't going to 1031). I've novice enough I don't know if there are other perks I could use to sell him on the idea. I realize it will totally depend on his situation and reason for selling. But I want to hear thoughts before pitching to him. Thanks in advance.