Off market abandoned property absentee owner ARV

[Wendy Busa]

1st time investor looking to wholesale an off market, abandoned property, owner lives in another state. Trying to figure out the ARV, but since I do not have access to the inside of the property I do not know what it would cost to rehab. Considering the year it was built, the exterior condition, I can only assume it will be a complete rehab. Since, this would be my first purchase, I have contacted a realtor to write the offer and it will include a contingency for a walk thru. I would have to figure there may be asbestos and there is definitely clean up to do. Based on the few comps in the area and working with the 70% rule, do I write an offer based on the worst case scenario?

I am trying to watch videos and am attempting to read a book, but will not have enough info. I truly appreciate any information you can share. Thank you.