I need rehab advise

[Diego Garcia]

So I am looking at this house that an older couple owns. They have very old taste so the house needs some cosmetic work, but it is so old that the electrical stuff is out of code. The contractor said the house will need to be rewired and it also needs an HVAC. Could there be expensive surprises behind the walls? How likely is it? The house also has a big crack on the floor in the basement and the floor is not level. Coild this be a problem with the foundation?