One of the best ways is to get your hands on a comparable market analysis. See what price similar properties have sold for in the past and find out the listing price of others currently on the market.
It is important to examine the fixer-upper carefully and figure out how much it will cost to fix any defects or repairs. If you are unable to get in, talk with nearby neighbors about the home’s condition.
You can also do your own cost comparison by researching comparable properties recorded at the local county recorder’s and assessor’s offices, or at websites specializing in property records. If the property is in foreclosure, you should get as much information as possible from the lender.