Once the home inspection has been identified a wet basement, then there is work to be done to identify the source of the leak. This typically involves some demolition work of drywall and flooring, in order to establish the extent of the damage.
The next step involves the scope of repair. For example, an excavator or digging by hand may be required to reach a failed perimeter drainage system along the exterior wall. Unfortunately, the drains in this case are at the elevation of the footings, which are below the foundations. You can let your imagination run wild here to estimate the cost. It certainly will for the contractor you employ.
Finally and most important, if you are a buyer of such a property, be sure to get estimates for the repair prior to the subject removal date. You will need to know the risk to your finances that this issue can present.