Updated almost 5 years ago on .

Seller Financing Advise!
So I am just finishing up a remodel. The home owners are going to sell there rental, (were they have been staying during remodel), when they move back into there residence. The purpose of selling there rental is to fund the building, of a new construction home in which they will sell. How could I approach the subject of selling me there rental with owner financing. What benefits would they have.
My thought process is, if they carry the financing they could do a Heloc. They could lock in a 3 percent range interest rate and then charge me say 7 percent effectively making 4 percent off me on there money. Does this sound good?
What other money would they save?
This would give me some time to renovate rent and then get conventional financing. What am I missing?