potential single family deal

[Justin A.]

I talked to the a seller and the situation is he wants around 350k for his house with a mortgage roughly at 290k. The comps in the area is around 445k but thats not true ARV value. Those comps were dated but well kept properties, so i figure after im done with the property its worth more? so if i did the math .70 x 445k - (repair cost 20k)= 291500 is the most i can offer? not a deal im assuming?

I have two issues, if the property is already in relatively good condition, how would you suggest this be flipped? or could i just subject to and rent it out? I estimate the the rehab cost left to be done to this house is 15-20k. which brings me to another issue and thats the rehab would take less than a month. wouldnt i need to hold it for 90 days before i can resell?

and 2.... he currently has it listed with the realtor. if this is a deal, should i go through the realtor or himself? (he contacted me himself due to his realtor being out of state for two weeks) what would be a good strategy going forward? 

Please advise. thanks