Basement Wall Collapse

[Mandi Baxter]

I am a relatively new investor and I am looking for your knowledge on this situation I found. 

I am driving for dollars and stumbled upon a property that has been abandoned. The information I have gathered so far tells me the owner passed away and he owed the state a lot of money so they may own the property (I am working on confirming this). I did find out from someone who was a family member of the deceased owner that a few years ago when we had some crazy weather and flooding one of the basement walls of the property caved in. This source hasn't seen the damage to verify the extent of the damage. I know that foundation repairs are a huge expense so I will do my due diligence and verify costs of repairs prior to buying the property. 

My questions are this, how much would you expect to pay for that kind of repair? Google is telling me $20k, I understand it can vary a lot in todays market but I have never dealt with foundation repairs so I don't have anything to base this off. I just want an idea so I have an idea what price MIGHT make this property worth it. 

Second question, if the damage is extreme, I'm considering if the house itself was also flooded now I might have mold, water damage, plus the foundation issues, at what point do you determine it makes more sense to tear down the property and build a new one? 

I would consider this land in a good location and know at least 2 people who maybe interested in buying it if I could repair or rebuild it.