Flipping a multi level house / weird layout

[Dan Porter]

Hello everyone and thank you in advance! I am long time BP listener (2017), and am looking at what would be my first flip. I have ran the numbers and am confident that the project would have great profit margins- assuming that my ARV is correct that is. I am having trouble setting an ARV because the house was built in 1966, and the layout feels awkward. The rooms flow well, but there are 4-5 steps going down to the dining room/ kitchen, another 4-5 down to the basement, and 4-5 going up to the second floor from the entry way, and 4-5 going up to the 4th bedroom. So essentially there are 5 different "levels" in this house.

I currently own a split level LTR, and am considering this property, but I was wondering if anyone could give me insight as to how this layout would effect the ARV? should I factor an additional 15% into my offer? 25%?

All help and advise is very appreciated!