How much of a concern are water stains around the foundation?

[Chad Mitchell]

I'm calculating rehab costs for a rental property, and the inspection revealed water intrusion around the foundation in the basement.

For an image, see: https://imgur.com/a/iXA6kBu

I've heard to walk away from deals involving foundation issues, so I wanted to check with others who have dealt with similar issues. How much does this cost in a typical case vs a worst case scenario?