Because it's not unusual to find a property for $20k that needs $100k and 6 months or more worth of work.  

I own the business but don't build equity in it (unusual franchise deal).  

They are not nearly as unusual as they used to be.

It is not unusual for certain utilities to become a lien on the property if not paid.

Unless one is in a very unusual business where the lions share of search volume is concentrated on a few phrases (e.g. there are only a few ways to search for a bail bondsman).

What you are looking for is not impossible, but unusual.

While this is not normal, it is not really unusual. 

So if the tax value ends up being more than that, use those for evidence.It's not unusual for homes to be valued less than others. 

I'd say $200/SF and up for small to medium scale MFH is not unusual in SD.  

@Jorge PenaI apologize in advance for how technical this response is, but I think it's worth your while to read it.The solution you're following is, bar none, accepted in renovation circles as the most foolproof yet expensive way to fix a basement HUMIDITY problem.However, it is highly unusual for a professionally-constructed house built any time in the last hundred years to be so situated as to have a truly severe humidity problem and little or no outright flooding.