Creative Financing Help!

[Lawrence Adeniseun]

Hello all, Thanks in advance for the words of wisdom. This is my scenario, the seller is trying to get out of a duplex he rents. One of the rooms in the duplex recently experienced fire damage. He still owes 50,000 on the house and his mortgage is 400 a month. He told me before the fire he was collecting about 1100 a month from the duplex. After renovation rents should go up. He is looking to sell for 126000. Estimated ARV is 160,000. The duplex has two rooms on each side. Based on the little experience I have, this scenario, in my opinion, calls for a lease option. But I'm not too sure, how would you structure the terms so that it’s a win, win for both parties? Could other strategies be implemented? Subject 2? Should I stop him before he starts renovations to get a lower purchase price and do the renovations myself? Thanks