The building's foundation and structure as a whole is solid, however there is much to be done in terms of TLC.

The bank (Wells Fargo) has placed a sump pump under the house and has done some foundation work. 

However, the most expensive starts to arise when you're looking at pool revival, roof replacing, foundational issues, and plumbing. 

I know it's not a calculator to answer your question, but hopefully it helps lay some foundation on how to approach this to keep relationship, not rip them off (by not knowing), and not lose money that could have been easily saved in the deal. 

I know insurance is not top of everyone's excitement list, but it is a foundation part, and an easy part to lower numbers by shopping different rates. 

There being a large cash outlay ( something foundational etc) within a few years of purchasing the property.

We had a foundation person look at it and he said "looks like a possible small leak under the slab foundation". 

I can only imagine the look on somebodies face when I told them the foundation is made of limestone!

Some thoughts about potential concerns:Insurance concernsStructural / foundation concernsPotential financing issuesPotential challenges in resaleAny best practices and suggestions for other things to look out for?  

All of those factor into the equation, and help determine which direction works best.I always suggest that just as in a construction project, you build your foundation.