Hello and Welcome!
First of all have you checked the comps to ensure sale price is accurate?
Second you need to check what his purchase price was, and if there was a loan. You can do that on realtytrac.com Membership is free 1st 7 days, just be sure to cancel on day 6. If they say a loan was given, you can then go to a mortgage calculator and figure out how much he owes by taking the term of the loan and interest rate and amount and figuring out what his payments would be. Generally speaking the smaller loans are 15-20 years in length.
You MUST know the comps, and how much he owes prior to talking to him.
DO NOT ask him to refi so you can do owner finance... that just wont happen. And from a business sense, you are mandating a VERY high interest rate on your loan from seller just so that it is profitable for him. But if he does have a loan, and the house needs a lot of work, tell him that you could take over the loan payments while you fix it up, then take out a new loan with the increased value of home and pay him out. If he says how do I know you will pay my loan, tell him you dont want to lose the house or lose any money paid towards mortgage already!
If you find out he is free and clear, then you can discuss seller financing, but not right away. Walk through the home, point out things you like but dont get excited just polite, then point out areas of concern and dont beat him up just kinda look worried. Along the way ask about his plans to move. Why Florida? Let him go on and on. Then say, Well why haven't you left yet? I have not sold house. Well I sure hope you and I can work something out! So What are you really wanting to get out of the sale? bla bla price.... Is that the best you can do? Ok, I could probably take 55k. Do you need all that cash to buy a place down there or are you just going to keep it in the bank? (if he says all cash to buy then you know you are not looking good.) If he says some to move and keep it in bank.
Now we move in for the deal... Well I like the house and I want you to get down to the warmth so I know one of us is in paradise. I am not very fond of banks after what they did to us. Let him answer and complain too. You know if I got a loan that they would make money off of you from your home? What if we said no more together, and you be the bank?! We can do seller financing. We set up a payment plan, an agreed interest rate, and a length of time, you make all that extra money from the interest and both of us win by not letting the banks in our deal! If I paid you cash they would charge me 3% and give you .25% to put it in savings. Well I need money to move. How much? Maybe we could work out a smaller down so I can help you move? ALSO- if he hesitates on seller finance, tell him you could agree to 60k if he does this with you.
The key to a deal is connecting. The deal will come. Rehearse the key points over and over. Then when you are there, just hang out with the guy. Become friends. LISTEN... LISTEN.... LISTEN to every thing he says. Let him bond with you. If he feels a bond he will want to work with you. If no bond no deal. If you are stressing the whole time in your head then no bond, which means no deal. So relax and chill with the guy. People respond to emotion over logic. You have to connect to the human being in order to get the deal.
Come with a Contract Drafted and ready to sign. Fill in notes like price and amount to give him as down for moving expenses.
This is the payment break down on a 10 year payout. $579.36 is monthly principle and interest. Tell him its like a bonus pension plan for him! Total interest is $9,524 over ten years. So really his sale price to you is almost $70,000. You talked him down to 55k now you are giving him 70K.
Good luck bud