You want to buy the property, I am assuming. First, I would look at what other homes, in good condition, have for assessments (property tax). Next, find out what homes have sold (preferably COVID and post COVID dates). Bring in a couple of contractors, walk them through, giving your thoughts, and ask for a quote to renovate. Now add the price to the asking price of the house. With this information you can offer a price knowing it will cost x amount to bring it up to the average selling price of homes on the street or neighborhood.