Remodel and flip in Brooklyn, NYC

[Alex Hal]

There's a house for sale across the street from my primary residence. The house was occupied by a woman who passed away and now her nephews are selling it. House prices have been appreciating quickly in brooklyn, ny in the past 5 years. The house is in a bad condition, almost everything is original from 1930. The owner wants 500k cash for it as is unlikely to get a mortgage. Talking to my gc, who did a good and quick job on my primary residence, estimates all in it'd be about 350-400k (including materials) in gut reno lasting 4 months. The ARV is 950k. There doesn't seem to be much profit after carrying cost, real estate fees and possible delays. I'm still hopeful that there are some innovative ways to make this work. Lowering the price being one. Agreement to have seller hold ownership until after repairs/sale to avoid carrying costs. Anything else?

Thanks in advance.