Got a contract on a house... how will this work?

[Ronald Fontenot Jr]

I have negotiated a contract on a home and am considering a creative exit plan. 

The seller is willing to allow me to secure the house with the contract at our price of 250k. ARV is 360k at minimum. Rehab is 40-50k.

Rather than wholesale it, which doesn't really work with the 70% rule of thumb, seller is willing to allow me to rehab the house while they technically still own it. This avoids me having to get hard money loan to purchase it as well as the cost of  that. Once rehab is done, the home will be listed with a realtor and sold at market.  When sold, seller gets his 250k, I get the rest. 

Is this a workable structure? How would I secure my interest once the house is listed since I think my contract would have to be canceled for the seller to list it?