Seller Financing Help

[Zac P.]

Looking at a duplex and owner says he would seller finance for 18-20% down and would hold the loan for 2-4 years. Does that mean I would need to have it paid off by then or,,, refinance what's left with a bank? I guess I would need to negotiate interest rates as well. I am new to this seller financing thing, any helpful input would be appreciated! What are your experiences with seller financing and what terms did you agree to? Thanks guys!

Also, this would be for buy and hold.