Unfortunately your question leaves a lot of blanks but here is some general information. Have a licensed contractor give you an estimate of what it will take to complete the house. Once you know the cost of finishing then you can make an offer that reflects those costs. Do you know whether any permits were pulled for the work done to date? If not you are going to have to backtrack to get building permits or inspections, all costs to figure in to the equation.
What type of financing are you considering? Unless you are paying cash you likely will need an FHA 203K loan with the finishing costs factored in.
Good luck.... more