Also, dry everything out in the basement but I wouldn't make any repairs until you get this sorted out... and depending on the extent of the damage, don't let the restoration company do the repairs without getting some other bids.

I agree with Drew to add at least 10% on top of your construction bid. 

If the agent/listing disclosed it needs work, selling as-is but that you likely wouldn’t win bid with an inspection contingency, then you decided not to have it inspected, that’s a different, hard lesson.

Your best bet is to consult with a few contractors to get some bids and go from there. 

I would get a few bids first from a contractor and then talk to a realtor/appraiser to see what the numbers look like 

There were many bids, and hours of discussion over how to properly proceed once all of this had come to light.  

There's a lot of competition for both SFHs and MFs in GR, but SFH owners NEED a place to live and I find I cannot and don't want to compete with them in a bidding war, as I simply can't make my numbers work.Buy a duplex and Owner Occupy the one side.  

Bring a local GC with you when you go so they can get a rough idea of a bid for renovation.

So if the lien amount is $1000 and you bid and win it at $1,100.   

.- at Home Depot always aks for better pricing at their bid room.