Does anyone have any experience on sloping floor in foundation?

[Alice Chau]

Hello,

I have put down an offer on a duplex in the Bay Area and did an inspection on the foundation and found that the floor was sloping due to the soil in the area. The inspector said that the fix or re-leveling would cost $15K/unit, and it could potentially happen again because of the soil.  The structure and strength of the foundation are good; however, I am worried about the sloping.  Does anyone have any experience with this and could share your experience or advice?

Thanks in advance,
Alice