For a Malibu? I would not risk it. I had a buddy who picked up two Flood/salvage title 2002 35th anniversary Camaro SSs. He got a good deal and you could see the water line. He was just going to use them for parts. 6 years later both run strong with no problems. He did replace the carpets, drain the fluids and go through the undercarriage.
Really depends on the car and what you are going to do with it.
If you bought it and were in an accident, whether your fault or not, what would the insurance company pay on an already salvage titled vehicle? I think that's how you could lose your shirt on this deal.