closing date 120 days from mutual acceptance

[Michael Paul]

I've found a property that has had four offers accepted and then the buyers have backed out. The property is currently off market. I plan to contact the sellers and and determine if they know why it's being rejected by the potential buyers and what they would be willing to take for the property. I believe the prop. is owned free and clear but either way my thought is to agree to a price with the seller with a closing date 120 days out, make the necessary improvements and assign contract or sell. I estimate a $100K spread between purchase price and ARV. If repair costs pencil out in the equation, what would be the best way to structure the contract? Fix up cost would be on me and earnest money would be in form of a promissory note. Too far out of the box? Genius or nuts?