REO Advice -when To Place Offer

All, I just viewed a bank REO this afternoon. Bank wants$100K, property has been on the market nearly a year. Comps in the area are $150K. By my esitmate, house needs about $30K-40K worth of work to make it marketable. I have a contractor going out next week to itemize the repairs. I am thinking of offering around $70K. Should I wait until I get the repair estimate & include it with my offer or do I just go for it? Thanks in advance!