Urgent, please help!

[Corey Keller]

I have a motivated seller currently meeting with a rehabber. He inherited the property when his parents passed, come to find out the house was copper mined, basement COMPLETELY flooded(up to the floor joist - which are apparently ruined) and from what he's saying the house needs to be torn down.

There are about $50k in back taxes owed and he has until the 15th to pay $4,400 cash to the county. I haven't been able to get a hold of my REA, and the comps I'm finding online are over a mile away. I'm finding myself stuck, but feel like this could be an amazing opportunity since the property sits on 3/4 acre in the heart of the city, which leads me to believe it can be subdivided.

He also said he would be VERY happy to get $70-75k for the property, so should I offer him around $15k and offer to take care of taxes/closing costs? 

Am I in over my head on this one?!