What changes the scope
Water source
One leaking crack is different from groundwater around the entire perimeter.
Interior drainage
Project length, access and sump needs affect the amount of work.
Exterior work
Excavation, access, wall condition and drainage all affect scope.
Existing systems
Old drain tile or sump equipment may need repair or replacement.
Why an inspection matters
An estimate is more useful after the contractor can see where the water is entering and what system is already in place. Pricing based only on a phone description can miss the actual cause.
Ask what the proposed work is solving
Wisconsin requires a basement-waterproofing seller's analysis describing the water problem and the specific methods and materials proposed before a contract is finalized. That makes the diagnosis and scope especially important.
Homeowner reference: Wisconsin DATCP basement waterproofing guidance.