I agree with Jack, from the sounds of it, this is going to be an expensive venture to repair it back to livable space. The physical broken pipes are an easy repair, what's not so easy is eradicating the mold and most likely extensive damage caused by the burst pipe. My guess is that the water ran a good long time before it was found and turned off and nothing was done but turning off the water, so plaster and drywall will be shot, floors will be buckled and mold will be rampant. Even with you doing most of the work, I suspect that the repairs will top Jack's estimate very easily. What I would recommend is to hire a contractor to assess the damage and provide an estimate for repairs BEFORE you start trying to buy the place. IMHO, it will be money well spent.